For women with regular menstrual cycles, ovulation is relatively fixed, is 14 days before the next menstrual period, for example, is the 15th menstrual period, then 1 is ovulation, 2-3 days before and after ovulation are easy to get pregnant time period. However, if the female friend’s menstrual cycle is irregular, this situation is not able to calculate the ovulation period, but should take the following two methods: 1, you can use ovulation test paper, in the 10th day of menstruation to start continuous application of ovulation test paper to check. It is best to fix the morning urine, because the morning urine hormone content is more stable, if there are two red lines as deep as, and in the gradual weakening, this is to enter the ovulation period. 2, the application of ultrasound to detect the development of follicles, follicle development to about 2cm will begin to ovulate, and the arrangement of coitus at this time will increase the rate of conception. But do not advocate the use of ovulation, safe period contraceptive methods, because the safe period contraceptive methods are not reliable.