Generally speaking, the menstrual cycle is not more than a few days apart. The reason for menstruation is that the ovaries secrete two hormones each month as the follicles develop, one hormone is estrogen and the other is progesterone. Progesterone is secreted after ovulation and usually lasts for about two weeks after ovulation. If there is a pregnancy during these two weeks or so, the estrogen and progesterone remain in a state of growth so that there is no menstruation. If there is no pregnancy for two weeks and it lasts for two weeks, the estrogen and progesterone levels will automatically decrease and you will have your period. It is not always possible to determine how many days after your period you are pregnant. If the cycle is supposed to be 30 days long and you don’t get it by 30 days, you can be pregnant. In general, pregnancy is determined by testing for human chorionic gonadotropin after pregnancy, and there is a rise in the process. The most sensitive test strips nowadays may be positive about a week or eight to nine days after pregnancy, but not necessarily. The sensitivity of the concentration of each test paper is related to the individual test, so generally if you have not had your period for more than a week, you should be able to detect whether you are pregnant. More tests are needed as to whether the pregnancy is normal or not, and whether the location of the pregnancy is normal. Content source: Dr. Yurai