I had sex three days after the water was turned on.

Hydrotubation is the abbreviation of fallopian tube hydrotubation, which is a common method to detect whether the fallopian tubes are unobstructed. Having sex three days after water perfusion does not guarantee pregnancy. Successful pregnancy is related to many factors. Unobstructed fallopian tubes are one condition. It is necessary to ensure that all conditions are met in order to successfully become pregnant. At the same time, if one cannot get pregnant after having sexual intercourse without contraception for a long time, it also depends on whether the man also has fertility problems.

Assuming that a menstrual cycle is 28 days, the 1st to 7th days of menstruation and the last 4-5 days of the cycle are the absolutely safe period when ovulation has not occurred or the egg has died; the remaining days are the relatively safe period, because ovulation may be advanced or postponed a few days due to many factors, so it is called relatively safe.

Although women ovulate mostly in the middle of their menstrual cycle, the ovulation time can be advanced or delayed due to factors such as the external environment, temperature, mood, and health status. Some women may experience extra ovulation when stimulated by sexual intercourse, which means that they may release 2 or more eggs in one menstrual cycle. Therefore, it is possible to get pregnant even during safe period.