To determine which side is ovulating, it is recommended to determine this by ultrasound, through which you can clearly determine on which side there is a follicle and whether it is normally expelled. Normally, each menstrual cycle a woman will have a dominant follicle that is expelled, alternating between the right and left ovary, or on one side consecutively followed by alternation. To determine which side ovulates, it is recommended to monitor the follicular development process by ultrasound to find out which side has the dominant follicle, and the side with the dominant follicle will more often than not ovulate. The ultrasound test for follicular development not only determines which side is ovulating, but also gives a general idea of when ovulation is occurring. For those who have fertility requirements, it is recommended to have intercourse during the ovulation period to have a higher chance of pregnancy, while for those who do not have fertility requirements, effective contraception is required during ovulation.