Enter your last period and cycle length to see your fertile window and likely ovulation day on a simple calendar—plus daily pregnancy odds. Note: <0.1% means less than 1 chance in 1,000. Peer-Reviewed Science Updated Aug 2026 See Methodology Did we solve your problem today? 👍Yes 👎No ✕ Sorry to hear! What went wrong? Not … Read more
Use this pregnancy due date calculator to work out your baby’s estimated due date (EDD), how many weeks pregnant you are, and which trimester you’re in. Enter the date of your last period, conception, intercourse, IVF transfer, or an early ultrasound. Calculate based on Last Period Conception Intercourse IVF Ultrasound Calculation method Last Period DateConception … Read more
See your estimated pregnancy odds for each day in a typical cycle. Enter the start date of your last period and your average cycle length to see a research-based calendar of approximate chances. If you want to calculate how many weeks pregnant you are, use the Gestational Age Calculator. Note: <0.1% means less than 1 … Read more
Enter the date and details of one encounter to see a research-based estimate of your pregnancy chance for that single event. The result is a statistical model, not a diagnosis. This calculator shows a statistical estimate based on research averages and the details you enter. It cannot confirm pregnancy, rule out pregnancy, or replace advice … Read more
When you are choosing birth control, it is easy to focus on the method itself, but how you use it also matters. The gap between perfect use (no mistakes) and typical use (real life) can change your pregnancy risk in a meaningful way. What “perfect” vs “typical” use means Perfect use Taking the pill at … Read more
Some contraceptive pairs can reduce protection or add risk. If you want to use two methods at the same time, it is usually safest to choose options that complement each other. The combinations below are ones that guidelines generally advise against, together with alternatives you can discuss with a clinician. Pairs you usually should not … Read more
Curious how your lifestyle and health affect your odds? This advanced calculator lets you add details like age, BMI, and more for a more detailed pregnancy chance estimate. Intercourse times ? Count any events you want to estimate for, regardless of time period. Female age ? Enter the age in completed years of the person … Read more
Using two birth control methods at the same time can lower pregnancy risk, especially if at least one method is less dependent on perfect day to day use. The calculator below gives an approximate estimate of protection when you combine methods under typical or perfect use. It is a modelling tool, not a substitute for … Read more
Method One Male CondomCombined pill (the pill)Withdrawal methodHormonal IUDCopper T IUDFemale sterilizationMale sterilizationContraceptive patch (the patch)MPA/DMPA shotProgestin-only pillVaginal ring (the ring)Contraceptive implant (the rod)Symptothermal methodOvulation methodTwoDay methodStandard Days methodSpermicides (most types)Female CondomDiaphragm (with spermicides)Parous Sponge (female)Nulliparous Sponge (female)Lactational Amenorrhea Method Use Quality TypicalPerfect Method Two (Optional) NoneMale CondomCombined pill (the pill)Withdrawal methodHormonal IUDCopper T IUDFemale … Read more
Some people choose to use more than one birth control method at the same time. This page summarises combinations that expert guidance from organisations such as the CDC and WHO generally considers reasonable for lowering pregnancy risk, while keeping STI protection in mind. The best combination for you depends on your health history, medicines, and … Read more