How many days after sex can you use a test strip to detect pregnancy?

After intercourse, the combination of sperm and egg has no contact with the mother before the embryo implants, so the mother cannot feel it. After the embryo implants, the combination of sperm and egg will produce a substance, which comes into contact with the uterine wall and turns into fluff. After the egg is fertilized, it takes about 4-5 days to go from the fallopian tubes to the uterus, and stays in the uterine cavity for 3-4 days. Therefore, this process takes about 7-9 days in total. In other words, after a woman is actually pregnant, it can be tested whether she is pregnant about 1 week to 10 days.

Using test strips to test pregnancy is not very accurate. It may be affected by the quality of the test strips and the influence of body hormones, resulting in false negatives or positive results. The sperm survival time can only reach 5 days. If you are having sex during the ovulation period, you can use a test strip 12-14 days after sex to test if it is a weak positive. If you have sex within 5 days before ovulation and need to postpone your period, in other words, if you have not had your period by January, and if you use a pregnancy test strip to test it, it will show a weak positive result. It is best to go to the hospital outpatient department to check your blood hcg gonadotropin, which is the most accurate.

If your menstrual period is relatively regular and your menstrual cycle is about 28 days, you can use an early pregnancy test to check whether you are pregnant at least 15 days after having sex. However, if you have irregular menstruation, a long menstrual cycle, or delayed ovulation and late embryo implantation, you need to postpone the on-site sampling of the early pregnancy test paper accordingly. In general blood tests, hcg gonadotropin is more sensitive than early pregnancy test strips and can detect possible pregnancy at an earlier stage. In the end, ultrasound examination can be used to confirm intrauterine pregnancy and eliminate the possibility of ectopic pregnancy.

Generally, sperm and egg combine to form pregnancy after sexual intercourse. Theoretically, it can be detected by early pregnancy test paper 10 days after sexual intercourse.

The basic principle of early pregnancy test strips is to test the HCG level in urine to see if it has increased. If the HCG level in urine rises, the early pregnancy test paper will generally show a positive result with two bars, which means that the woman may be pregnant. Generally, after the sperm and egg combine to form an embryo, HCG will be secreted. About 10 days after the couple's intercourse, under normal circumstances, the HCG level in the urine will increase, and the early pregnancy test paper will show a positive result. However, due to the different sensitivity of early pregnancy test strips and the dilution degree of female urine, early pregnancy test strips may give false negative results. Therefore, in clinical medicine, it is generally recommended that women take early pregnancy test strips after menopause, and the accuracy will be significantly improved.