The date of conception can be estimated based on ovulation, ultrasound measurements, and the time of the last menstrual period to project the approximate time frame for conception, but it usually cannot be pinpointed to a specific day.
1. Estimation based on ovulation: For women with regular menstrual cycles, ovulation usually occurs about 14 days before the next menstrual period, and sperm can usually survive for 1 to 3 days after entering the female reproductive tract, so the 3 to 4 days before and after ovulation are the dates of easy conception.
2. Estimation based on ultrasound measurements: Women with irregular menstrual cycles can measure the size of the gestational sac, the size of the fetal buds, the length of the fetal head and buttocks, the diameter of the top and bottom of the fetus, and so on, according to the formula for estimating the week of gestation, and then estimate the possible date of conception.
3. Estimation according to the time of the last menstrual period: Clinical practice generally does not use the date of conception to estimate the week of pregnancy, but mostly uses the first day of the last menstrual period as the beginning of the gestation period.
After finding out that you are pregnant, you should undergo regular obstetric checkups to detect and intervene in abnormalities of the mother and fetus through systematic monitoring and health care of the pregnant woman and the fetus in a timely manner.