In about 3 days before and after the day of ovulation coitus is easy to conceive, specifically to which moment of the day is easier to conceive is not easy to say, under normal circumstances, the egg can survive for 2 days after discharge, sperm can survive for 3 days after discharge, want to successfully conceive to grasp the time of ovulation. Ovulation time can be calculated according to the regular menstrual cycle, the menstrual cycle in about 30 days of women, from the first day of the menstrual cycle, ovulation in the 15th-16th day or so. Women with irregular menstruation can not be projected according to this method, you can use ovulation test paper to monitor the urine at home, the test process of weak positivity changes to strong positivity, and then changes to weak positivity, indicating ovulation. You can go to the hospital for ultrasound to detect follicular development, and ovulation occurs when the follicle reaches a diameter of about 18-25 millimeters.