Predict your next period with a 3-day window from your last period date and average cycle length. You also get the next two start dates, today’s cycle day, a late flag, and the earliest reliable test day if late. Last period start date If left blank, the calculator will assume 28 days ago. Average cycle … Read more

Vasectomy is very effective, but failures can happen—most early (before semen analysis is clear) and rarely years later from recanalization. This calculator estimates annual and cumulative risk bands using your procedure type and time since surgery. It’s educational only; if your partner’s period is late, test early and speak with a clinician. Months since vasectomy … Read more

Tubal ligation is very effective, but failures can occur—and when they do, ectopic pregnancy is more likely. This calculator estimates your annual and cumulative risk bands based on procedure type, time since surgery, and whether a reversal was done. Use it for education only; if you have pregnancy symptoms, test early and contact a clinician. … Read more

Use this calculator to estimate when you’re most likely to ovulate after a cycle of clomiphene (e.g. Clomid) or Letrozole (e.g. Femara). Enter your regimen and last pill date to get a likely ovulation window, the earliest reliable test day, and an estimated due date if you conceive. Educational only—timing varies and clinical monitoring is … Read more

Enter the time of your first positive OPK and your typical surge length. This calculator estimates your ovulation window, the best days to try, and the first reliable pregnancy test day. Date of first positive OPK Time of first positive (approx.) Your typical surge length About 24–36 hoursAbout 12 hours (short)About 36–48 hours (long)Not sure … Read more

A missed or late period can be stressful. This calculator weighs your cycle history, how many days late you are, recent protected or unprotected intercourse, and any test dates to estimate whether pregnancy or a delayed cycle is more likely, plus when to test or retest. Not sure when your period is due next? The … Read more

Check if you meet LAM (Lactational Amenorrhea Method) criteria while breastfeeding. Enter baby’s age, feeding pattern, night feeds, and period status to see if LAM applies, how effective it is, and when to switch methods. Baby’s age (months) Exclusive breastfeeding (%) 100% Approximate how much of baby’s intake is breast milk (no regular formula/solids = … Read more

Estimate your IUI pregnancy chance using age, trigger use, semen quality, and which attempt you are on. See the per-cycle estimate and cumulative chances across the first three IUIs. Female Age IUIs this cycle Single IUIDouble IUI (two inseminations this cycle) Semen Quality (quick) Auto — use detailed values if enteredNormal parametersLow count/motility Tip: leave … Read more

Reviewed by Dr. Sony Sherpa, MBBS, MD on Dec 22, 2025 Use this calculator to estimate twin odds for one pregnancy. Use the Optional details section to get more precise results. Female age Prior births Family history of twins NoYes (maternal side)Yes (paternal side)Yes (both sides) Have you had twins before? NoYes Fertility treatment None … Read more

Enter cycle timing and bleeding details to compare implantation spotting with a period and see when to take a pregnancy test. Timing Do you know your ovulation date? NoYes Start date of your last period (LMP) Average cycle length (days) Ovulation date Bleeding started on Bleeding details Pattern (pick the closest) Only when wipingSpotting on … Read more