Can a test strip detect pregnancy after 13 days of intercourse?

It is possible to detect pregnancy 13 days after intercourse, but if the test is negative, the possibility of pregnancy cannot be completely ruled out. Early pregnancy test strips determine whether you are pregnant by testing the hcg gonadotropin in urine. Generally, women with regular menstrual cycles can only be tested for pregnancy after the onset of menopause. If your menstrual cycle is irregular and unexpected ovulation occurs, it may take 40-45 days of amenorrhea to be detected. Early pregnancy test strips are only an auxiliary method of pregnancy detection, and you cannot completely determine whether you are pregnant by early pregnancy test strips. Early pregnancy test strips may also give positive and false negative results. It is recommended to go to a regular hospital to check the blood progesterone value and hcg to determine whether you are pregnant.

For people with normal ovulation period, most of the cases cannot be detected, but a few people with early ovulation period can be detected. If you really want to know whether you are pregnant, a blood test of human chorionic gonadotropin (HCG) can be detected, but it can only test whether you are pregnant, but cannot confirm whether it is intrauterine pregnancy or ectopic pregnancy. If the menstruation is delayed and the HCG test is positive, you can go to the hospital for an ultrasound examination about 40 days after the menstruation to confirm whether it is an intrauterine pregnancy.

By checking the blood hcg gonadotropin 13 days after intercourse, it can be definitively determined whether pregnancy is present. However, it is not possible to definitively determine whether you are pregnant through early pregnancy tests, and there may be false negative results. The main reason is that sperm can survive in the body for 72 hours, so as long as ovulation occurs at any time within 72 hours, pregnancy is possible. If you get pregnant on the 3rd day after having sex, it is during this time that the sperm and egg combine and the embryo implants.

It takes about 7 days for the embryo to implant. It takes about a day after the embryo implants for the blood hcg gonadotropin to rise. Therefore, by checking the blood hcg gonadotropin, it is possible to determine whether you are pregnant or not. However, the urine test still needs 3-5 days. If the early pregnancy test is negative, it is necessary to test again after 3-5 days.