This site has five pages about pregnancy — the app lane, the contraction timer, the movement recorder, the hospital bag, and leave. Four of the five link only to each other, to the homepage, and to the newborn hubs. Nothing here ever told you how far along the pregnancy is, which is the one number every conversation about pregnancy is built on. This page starts there, then routes you to the page that matches what you are actually doing.
Enter the first day of the last menstrual period and the usual cycle length. The calculator restates the published dating convention — ACOG's 280 days from that first day — and reports which published boundary that arithmetic crosses. It keeps the bands the sources publish: the four way split of “term”, and the three trimesters as ACOG writes them.
Three things this page keeps straight, because a dating number is exactly the kind of figure that gets treated as a verdict.
The 280-day convention is where dating starts, not where it ends. ACOG's guidance has the practice determine and document the gestational age and estimated due date as soon as the first accurate ultrasound or last-period data is available, and treats a pregnancy with no ultrasound confirming or revising the date before 22 0/7 weeks as suboptimally dated. If this page disagrees with your chart, your chart is right.
The published convention quietly assumes a 28-day cycle with ovulation on day 14, and ACOG states in the same document that this “does not account for inaccurate recall of the LMP, irregularities in cycle length, or variability in the timing of ovulation.” That is why this calculator asks for the cycle length and shifts the implied ovulation day rather than pretending.
ACOG reports that “approximately one half of women accurately recall their LMP”, and in one study 40% of women who had a first-trimester ultrasound had the estimated date adjusted because the two datings disagreed by more than five days. An estimate built on a remembered date is still an estimate.
This page does not confirm a pregnancy, does not read a test, does not estimate the baby's size, and does not assess whether anything is on track. It does date arithmetic on a date you typed in. Those are different things, and only the first one is happening here.
The dating convention, the trimester boundaries, and the term classifications are restated from published guidance. Where the sources disagree with each other, this page says so instead of quietly picking the tidier number.
| Figure | What the published guidance says | Source |
|---|---|---|
| Where the due date convention comes from | “By convention, the EDD is 280 days after the first day of the LMP.” The American College of Obstetricians and Gynecologists states this in Methods for Estimating the Due Date, and it is the arithmetic this page restates. It is a convention, not a measurement. | ACOG Committee Opinion 700 (2017) |
| The assumption hiding inside 280 days | “This practice assumes a regular menstrual cycle of 28 days, with ovulation occurring on the 14th day after the beginning of the menstrual cycle.” ACOG also states this convention “does not account for inaccurate recall of the LMP, irregularities in cycle length, or variability in the timing of ovulation.” That is why this page asks for the cycle length instead of silently assuming 28. | ACOG Committee Opinion 700 (2017) |
| The convention's own weak point | “It has been reported that approximately one half of women accurately recall their LMP.” In one study, 40% of women who had first-trimester ultrasonography had the estimated due date adjusted because ultrasound and last-period dating disagreed by more than five days. The date your practice assigned is the real one. | ACOG Committee Opinion 700 (2017) |
| The date that actually governs | “As soon as data from the last menstrual period, the first accurate ultrasound examination, or both are obtained, the gestational age and the estimated due date (EDD) should be determined, discussed with the patient, and documented clearly in the medical record.” And a pregnancy with no ultrasound confirming or revising the date before 22 0/7 weeks “should be considered suboptimally dated.” | ACOG Committee Opinion 700 (2017) |
| When the dating changes | Before 14 0/7 weeks, if ultrasound dating differs from last-period dating by more than seven days, the estimated due date should be changed to the ultrasound date; before 9 0/7 weeks a discrepancy of more than five days is reason enough. The earliest ultrasound is the one that counts. | ACOG Committee Opinion 700 (2017) |
| Trimester boundaries, as ACOG writes them | The first trimester runs “up to and including 13 6/7 weeks of gestation.” The second trimester covers “between 14 0/7 weeks and 21 6/7 weeks” and continues through 27 6/7 weeks. The third trimester is stated as “28 0/7 weeks of gestation and beyond.” | ACOG Committee Opinion 700 (2017) |
| Preterm | “Less than 37 weeks and 0 days.” The late-preterm band is 34 weeks and 0 days through 36 weeks and 6 days. | ACOG reVITALize Obstetrics Data Definitions |
| Term is not one thing any more | “Term: greater than or equal to 37 weeks and 0 days using best EDD” — divided into early-term (37 0/7 through 38 6/7), full-term (39 0/7 through 40 6/7), late-term (41 0/7 through 41 6/7), and post-term (42 0/7 and beyond). ACOG and SMFM recommend the old habit of calling the whole range “term” be discouraged. | ACOG reVITALize; ACOG Committee Opinion 579 |
| The classifications the tool reports, verbatim | Every band the calculator reports is a published ACOG reVITALize definition, not this page's own wording: preterm is “less than 37 weeks and 0 days”; early term is “37 weeks and 0 days through 38 weeks and 6 days”; full term is “39 weeks and 0 days through 40 weeks and 6 days”; late term is “41 weeks and 0 days through 41 weeks and 6 days”; and post-term is “greater than or equal to 42 weeks and 0 days.” The tool classifies an age into these bands and adds nothing. | ACOG reVITALize Obstetrics Data Definitions |
| When movement is first felt | “Most women are first aware of their baby moving when they are 18–20 weeks pregnant.” If this is a first pregnancy it may be later than 20 weeks; if you have been pregnant before, movements may be felt “as early as 16 weeks.” A partner not feeling anything at 17 weeks is not a finding. | RCOG, Your baby's movements in pregnancy |
| Movement rises, then holds | “The number of movements tends to increase until 32 weeks of pregnancy and then stay about the same.” RCOG's guideline adds that although movements plateau at 32 weeks, there is no reduction in movement frequency in the late third trimester, and that movement should continue right up to labour — and during it. | RCOG patient information; RCOG Green-top Guideline 57 |
| Sources disagree about counting | RCOG: “There is no specific number of movements that is considered normal” and “there is not enough evidence to recommend the routine use of a movement chart.” A widely cited clinical review instead defines normal movement as “10 or more fetal movements in 2 hours.” This site follows the RCOG position — know your baby's own pattern — and says so rather than adopting the tidier number. | RCOG; RACGP Australian Family Physician |
| The one movement rule that is not optional | “Always seek professional help immediately. Never go to sleep ignoring a reduction or change in your baby's movements. Do not rely on any home kits you may have for listening to your baby's heartbeat.” That is the care team's call, not a page's, and it is not something a tool can assess. | RCOG, Your baby's movements in pregnancy |
| What reassurance actually looks like | After a single episode of reduced fetal movements, most pregnancies are uncomplicated — RCOG's guideline puts it at “70% of pregnancies with a single episode of RFM.” That is a reason to make the call, not a reason to skip it. | RCOG Green-top Guideline 57 |
| What this page cannot see | Whether there is a pregnancy at all, what an ultrasound showed, whether the dating was changed, how the baby is growing, or what your care team has told you. It does date arithmetic on a date you enter. That is a different thing entirely. | This page, stated plainly |
A number to count to is the most requested thing on this topic and the least defensible thing to publish. Here is the split, stated rather than hidden.
“There is no specific number of movements that is considered normal,” and “there is not enough evidence to recommend the routine use of a movement chart.” The position is to know your baby's own pattern and to treat a reduction or change from it as the signal. This site follows RCOG.
A widely cited clinical review defines normal fetal movement as “10 or more fetal movements in 2 hours,” felt while lying on your side and focusing. It is a definition used in clinical contexts, not a target a web page should hand a parent in the middle of the night.
If you adopt a target, a quiet hour becomes a false alarm and a busy hour becomes false reassurance. Neither is a judgment a page can make for you. Your care team can, because they know the pregnancy.
Reduced or changed movement means contacting your midwife or local maternity unit immediately, and RCOG states it as plainly as it can be stated: never go to sleep ignoring a reduction or change. Do not rely on home kits for listening to a heartbeat. That call is the care team's, not a tool's.
Five pages, ordered by the question in your head rather than by build date.
Operational readiness by stage rather than baby-size comparisons: prep, appointments, and the handoff into newborn tracking.
Open Is this the real thing?Time duration and spacing with a practice tool, and follow the care team's own go-in instruction.
Open Every rideHow to choose, fit and buckle a car seat, quoted from the sources that publish the method, plus the five places they disagree: one NHS trust's two-hour rule against the Lullaby Trust's statement that no such figure is published, the legal rear-facing age against the AAP's advice to wait as long as possible, whether a car seat is a safe place to sleep, where the seat goes, and the retracted study behind the age that was once published. Both sides shown, neither averaged.
Open How do I record movement?Record a movement session calmly, and escalate reduced or changed movement the way the published guidance says.
Open What do I actually pack?Power, food, paperwork, layers, and comfort — the partner's list, not a generic one.
Open How do I take the time?Work out the leave you have, when it starts, and what still needs a conversation.
OpenA first day plus a cycle length plus the published convention equals weeks and days. That is the whole calculation. There is no scoring, no rating, no comparison of this pregnancy to anyone else's.
A date that has passed reads “beyond the conventionally estimated date”, not “overdue”. The tool has never seen your chart, your scans, or your care team's plan.
A single “term” label for the whole 37-to-41-week span is discouraged by ACOG and SMFM, so this page shows early, full, late, and post-term separately instead of collapsing them.
Most pregnancy calculators assume 28 days and say nothing about it. This one takes the cycle length as an input and tells you the assumption it is shifting, because the published convention's weaknesses are exactly where it is least reliable.
No account, no save, no upload, no network call. Close the tab and the date is gone. The printable timeline exists precisely because nothing is stored.
Reduced or changed movement, bleeding, severe headache, vision changes, fever, or anything that worries you is a call to your midwife, maternity unit, or emergency services today. Never delay care to use a page.
Write in the dates your care team gives you, not the estimates from this page, and take it to the next appointment. Nothing here is stored anywhere else.
| Stage (published boundary) | Our date | To raise |
|---|---|---|
| First trimester | ||
| Second trimester | ||
| Third trimester | ||
| First movement felt (18–20 weeks) | ||
| Third trimester (28 weeks) | ||
| Estimated due date (convention) |
Every figure on this page is restated from these references. Your care team supplies medical guidance, including the dating, the monitoring plan, and the go-in instruction.
Two different questions, and this page keeps them apart. How far along is gestational age: the number of weeks and days since the first day of the last menstrual period, which is how the published convention counts. The due date is that first day plus 280 days — ACOG's Methods for Estimating the Due Date states the convention outright. The calculator above gives you both, adjusted for a cycle length you enter. What it cannot give you is your real date: your practice assigns that, and a first-trimester ultrasound usually confirms or revises it.
The published 280-day convention quietly assumes a 28-day cycle with ovulation on day 14, and ACOG says so in the same document — noting the convention “does not account for inaccurate recall of the LMP, irregularities in cycle length, or variability in the timing of ovulation.” So the calculator takes your cycle length as an input and shifts the implied ovulation day, which is a better estimate than pretending every cycle is 28 days. It is still an estimate. For a long or irregular cycle this is exactly the situation where the ultrasound date wins, and where you should use the date your practice gave you.
This site deliberately does not publish a target, because the guidance disagrees with itself. RCOG says plainly that there is no specific number of movements that is considered normal and that there is not enough evidence to recommend the routine use of a movement chart; a widely cited clinical review instead defines normal movement as 10 or more in 2 hours. RCOG's position is to know your baby's individual pattern, and that a reduction or change from that pattern is the thing that matters. A number off a web page cannot know your baby's pattern, so we follow RCOG. What is not optional: reduced or changed movement means contacting your midwife or maternity unit immediately, and never going to sleep ignoring it.
No, and no page can. A timer records duration and spacing; it has no idea what your care team told you, how far away the hospital is, or what else is going on. The cluster's contraction timer page is built to follow your team's own go-in instruction rather than to invent one, and this page does not publish a timing rule either. Call the number you were given whenever you are unsure; that is what it is for.
Use your clinic's date, every time. It is derived from your actual records, and ACOG's guidance has the practice determine and document the gestational age and estimated due date as soon as the first accurate ultrasound or last-period data is available. A pregnancy without an ultrasound confirming or revising the date before 22 0/7 weeks is described as suboptimally dated. This page does arithmetic on one date you typed in; your chart has the real information.
Published by DadYolked · Updated September 20, 2026 · Editorial standards and corrections