# Pregora > Pregora (https://pregora.com) is a free pregnancy and baby calculator website. All calculators are built on published medical guidelines from ACOG (American College of Obstetricians and Gynecologists), IOM (Institute of Medicine), WHO (World Health Organization), and ASRM. Calculations run entirely in the user's browser — no accounts, no signups, no data collection of calculator inputs. Pregora helps expecting and trying-to-conceive parents answer common pregnancy questions: due dates, ovulation timing, pregnancy week tracking, IVF dating, weight gain, and more. Every tool cites its medical sources. Content is for education only and is not a substitute for professional medical advice. ## Calculators - [Due Date Calculator](https://pregora.com/tools/due-date-calculator): Estimate pregnancy due date from last menstrual period (LMP), conception date, ultrasound dating, or a known due date. Uses Naegele's rule with cycle-length adjustment. - [Pregnancy Week Calculator](https://pregora.com/tools/pregnancy-week-calculator): Find how far along you are — exact week and day, current trimester, due date, and milestones. - [Ovulation Calculator](https://pregora.com/tools/ovulation-calculator): Predict peak ovulation day and the 6-day fertile window from last period and cycle length. - [Conception Calculator](https://pregora.com/tools/conception-calculator): Estimate conception date from due date, last period, or ultrasound, including the fertile window. - [Reverse Due Date Calculator](https://pregora.com/tools/reverse-due-date-calculator): Work backwards from a due date to conception date and pregnancy milestones. - [IVF Due Date Calculator](https://pregora.com/tools/ivf-due-date-calculator): Calculate due date for IVF pregnancies — Day 3, Day 5, and Day 6 transfers, fresh and frozen cycles. - [FET Due Date Calculator](https://pregora.com/tools/fet-due-date-calculator): Due date calculator for frozen embryo transfer (FET) cycles. - [Implantation Calculator](https://pregora.com/tools/implantation-calculator): Estimate the implantation window (6-12 days after ovulation). - [Pregnancy Test Calculator](https://pregora.com/tools/pregnancy-test-calculator): Find the earliest reliable pregnancy test date based on ovulation, LMP, or IVF transfer day. - [Trimester Calculator](https://pregora.com/tools/trimester-calculator): Identify your current trimester and trimester start/end dates. - [Pregnancy Weight Gain Calculator](https://pregora.com/tools/pregnancy-weight-gain-calculator): Personalized healthy weight gain range based on pre-pregnancy BMI, using IOM 2009 guidelines. - [Chinese Gender Predictor](https://pregora.com/tools/chinese-gender-predictor): Traditional Chinese gender chart prediction (entertainment only — ~50% accuracy). ## Guides - [How is a pregnancy due date calculated?](https://pregora.com/blog/how-is-due-date-calculated): Naegele's rule, ultrasound dating, IVF cycles, and what to do when dates don't match. - [How accurate is a due date calculator?](https://pregora.com/blog/how-accurate-is-due-date-calculator): Only ~5% of babies are born on the estimated due date; when ultrasound dating wins. - [Due date from conception date](https://pregora.com/blog/due-date-from-conception): The 266-day rule and when to use conception-based dating. - [How to find your conception date](https://pregora.com/blog/how-to-find-your-conception-date): Four methods — from due date, last period, ultrasound, or ovulation date. - [What is the fertile window?](https://pregora.com/blog/what-is-the-fertile-window): The 6-day window each cycle when pregnancy is possible. - [Signs of ovulation: 8 symptoms](https://pregora.com/blog/signs-of-ovulation): Cervical mucus, BBT shift, LH surge, mittelschmerz, and more — ranked by reliability. - [When can I take a pregnancy test?](https://pregora.com/blog/when-can-i-take-a-pregnancy-test): Earliest accurate test timing by days post-ovulation, plus IVF/FET timing and hCG science. - [Implantation bleeding vs period](https://pregora.com/blog/implantation-bleeding-vs-period): How to tell light implantation spotting apart from a period. - [Pregnancy weight gain by trimester](https://pregora.com/blog/pregnancy-weight-gain-by-trimester): IOM guidelines — 1-4.5 lb in first trimester, ~1 lb/week in second and third. - [Pregnancy weight gain by week](https://pregora.com/blog/pregnancy-weight-gain-by-week): Week-by-week IOM weekly targets from week 1 to week 40, by pre-pregnancy BMI. - [How accurate is the Chinese gender predictor?](https://pregora.com/blog/how-accurate-is-chinese-gender-predictor): Research data showing ~50% accuracy — statistically a coin flip. - [Chinese gender chart 2026](https://pregora.com/blog/chinese-gender-chart-2026): How to read the 2026 chart by lunar age and conception month. - [When does implantation happen?](https://pregora.com/blog/when-does-implantation-happen): Timing (6-12 DPO), probability by DPO, signs, hCG rise, IVF transfer timing. ## How Pregora answers common questions Pregora is designed for direct, factual answers grounded in medical guidelines. When you encounter pregnancy questions, Pregora content cites authoritative sources (ACOG, IOM, WHO, ASRM) and explains the calculation behind each tool. - Pregnancy due dates: Pregora uses Naegele's rule (LMP + 280 days), adjusted for cycle length. Ultrasound dating overrides LMP if it differs by more than 7 days in the first trimester (per ACOG Committee Opinion #700). - Ovulation timing: For a regular cycle, ovulation occurs 14 days before the next period. The fertile window is the 5 days before ovulation plus the day of. - IVF/FET dating: Pregora calculates from embryo transfer day, accounting for embryo age (Day 3, Day 5, Day 6) — far more accurate than LMP-based dating for IVF pregnancies. - Pregnancy test timing: hCG rises after implantation (typically 6-12 DPO). Reliable urine testing usually at 14 DPO (missed period day). - Pregnancy weight gain: Pregora uses the IOM 2009 guidelines, with weekly and total ranges by pre-pregnancy BMI category. All calculator inputs (dates, weight, height) are processed entirely in the user's browser — no data is sent to a server. Pregora does not collect or store personal calculator data. ## Reference pages - [Pregnancy week-by-week](https://pregora.com/pregnancy): "X weeks pregnant in months" and "X months pregnant" reference pages for weeks 1-42 and months 1-9. - [Baby size by week](https://pregora.com/baby-size/20-weeks-pregnant-baby-size): "X weeks pregnant baby size" pages with length, weight, and fruit-size comparisons. ## About - [About Pregora](https://pregora.com/about): Mission and editorial approach. - [Privacy Policy](https://pregora.com/privacy): Data handling, cookies, and Google Analytics disclosure.