January 1, 2024
Week 12
2nd Trimester
Jan - Mar
Apr - Jun
Jul - Sep
Find your most fertile days to increase your chances of getting pregnant. This tool estimates your ovulation date and fertile window based on your menstrual cycle information.
NOTE: This calculator estimates your fertile window based on your cycle length with ovulation occurring around 14 days before your next period. Every woman's body is different, and cycle lengths can vary. For the most accurate tracking, consider using ovulation predictor kits or monitoring basal body temperature.
This ovulation calculator provides an estimate of your fertile window and is not a guarantee of pregnancy or of birth control. The calculator assumes a regular menstrual cycle. If you have irregular periods, the predicted ovulation date may not be accurate. Always consult with a healthcare provider for medical advice.
During the first trimester, your baby's major organs begin to form, and the risk of miscarriage is highest. You may experience morning sickness, fatigue, and breast tenderness. By the end of this trimester, your baby is about 3 inches long and weighs around 1 ounce.
Often called the "honeymoon phase" of pregnancy, many women find relief from morning sickness during this period. Your baby's movements become noticeable, and you'll likely have an ultrasound to determine the gender. By week 27, your baby is about 14 inches long and weighs around 2 pounds.
The final stretch of pregnancy brings rapid growth for your baby. You may experience more discomfort as your body prepares for labor. Your healthcare provider will see you more frequently during this time. By birth, the average baby is 19-21 inches long and weighs 7-8 pounds.
Complete medical history, blood tests, and dating ultrasound.
Screens for chromosomal abnormalities like Down syndrome.
Detailed ultrasound checking baby's organs and structures.
Screens for gestational diabetes.
Checks for bacterial infection that can be passed to baby during birth.
A typical menstrual cycle runs about 28 days, although cycles between 21-35 days are considered normal. Understanding your cycle is key to identifying your fertile window.
Begins on the first day of menstruation. Follicle-stimulating hormone (FSH) stimulates follicles in the ovary to grow, each containing an egg.
The release of a mature egg from the ovary. This typically occurs mid-cycle, about 14 days before your next period.
After ovulation, the empty follicle forms the corpus luteum, which produces progesterone to prepare the uterine lining for a potential pregnancy.
The fertile window is typically about 6 days long—the 5 days before ovulation plus the day of ovulation itself. This is because sperm can live up to 5 days in a woman's reproductive tract, while an egg is viable for only about 24 hours after release.
Track your periods over several months to identify patterns and predict ovulation.
Best for: Women with regular cycles
Take your temperature each morning before getting out of bed. A slight rise indicates ovulation has occurred.
Best for: Confirming ovulation has happened
Check changes in vaginal discharge throughout your cycle.
Best for: Identifying approaching ovulation
Test urine for luteinizing hormone (LH) surge that precedes ovulation.
Best for: Precise timing of ovulation
Our pregnancy calculator provides estimates based on standard pregnancy durations and averages. The accuracy depends on several factors including:
While most pregnancies last approximately 40 weeks from the last menstrual period, only about 5% of babies are born exactly on their due date. Most deliveries occur within 1-2 weeks before or after the calculated date.
For the most accurate dating, consult with your healthcare provider who may use ultrasound measurements for dating.
The standard method for calculating a due date is Naegele's rule, which is:
For example, if your last period started on February 1, 2025:
This method assumes a 28-day cycle with ovulation occurring on day 14. For longer or shorter cycles, adjustments may be needed.
While uncommon, it is possible to ovulate during your period, particularly if you have a very short cycle or long periods. For example:
This is one reason why the "rhythm method" alone isn't considered a reliable form of birth control.
Most home pregnancy tests claim to be accurate from the first day of your missed period, which is about two weeks after conception. However, for the most reliable results:
Some sensitive tests can detect pregnancy 4-5 days before your missed period, but false negatives are more common this early.
Many factors can influence fertility in both men and women:
If you've been trying to conceive for over a year (or 6 months if you're over 35), consider consulting a fertility specialist.
Implantation typically occurs 6-12 days after ovulation, with most implantations happening around 8-9 days post-ovulation. During this process:
Implantation is a critical step in early pregnancy development, and successful implantation is necessary for pregnancy to continue.
Explore our comprehensive collection of guides and articles about pregnancy planning, fertility tracking, and reproductive health.
Explore our full collection of pregnancy and fertility articles, guides, and calculators to help you on your reproductive health journey.