The pregnancy calculator turns one known dating source into a consistent calendar: an estimated due date (EDD), current gestational weeks and days, trimester, calendar progress, an estimated conception date, pregnancy milestones, and the date ranges for early term, full term, late term, and postterm pregnancy.
It supports five actual modes: last menstrual period (LMP), an already assigned due date, a known conception date, IVF embryo transfer, and gestational age reported on an ultrasound. These modes calculate date relationships. They do not predict the day labor will begin or confirm pregnancy, embryo or fetal viability, fetal growth, or the start of labor. If a clinician or fertility clinic has already assigned an EDD, enter that date directly and use it for care-related decisions.
If methods disagree, do not treat the website as an automatic redating tool. The best obstetric EDD depends on how the pregnancy was conceived, whether the LMP is reliable, the earliest suitable ultrasound, and the full clinical record.
Enter the first day of the most recent normal menstrual period—not the day bleeding ended or a day of isolated spotting. The page accepts an integer cycle length from 21 to 35 days and starts at 28 days. Cycle length means the interval from the start of one period to the start of the next. Each day above 28 moves the EDD one day later; each day below 28 moves it one day earlier.
The adjustment still assumes ovulation roughly 14 days before the next period. An irregular cycle, uncertain LMP, or cycle outside 21–35 days should not be presented as an equally reliable LMP estimate.
No. An EDD is a reference point for the pregnancy timeline, not a prediction of labor. Use the EDD assigned by your clinician when one is available.
The page applies cycle adjustment only to regular cycles of 21–35 days. For irregular, uncertain, shorter, or longer cycles, use a clinician or ultrasound report instead.
LMP recall, variation in ovulation, and ultrasound measurement uncertainty can all contribute. The page does not redate a pregnancy automatically; a clinician should establish the final EDD.
The page adds 266 minus the embryo age to the transfer date, which is 263 days for a day-3 embryo and 261 days for a day-5 embryo.
No. This is calendar arithmetic; it cannot confirm pregnancy, viability, growth, or the actual conception date, and it must not be used to infer paternity.
根據最後一次月經、已有預產期、受孕日期、IVF 胚胎植入或超音波孕週，估算預產期、孕週、孕期階段、足月區間和日曆節點；僅供日期參考，不取代醫療建議。