There is no authoritative information on when a follicle 1.2cmx0.9cm ovulates, it may ovulate in 3-4 days, depending on the individual. Follicle is a kind of round bubble-shaped germ cells in the female ovary, at present, there is no relevant authoritative information about when the follicle 1.2cmx0.9cm ovulation. Generally, it is clinically believed that a 1.2cmx0.9cm follicle may ovulate after 3-4 days. However, due to the different hormone levels, physical health and other factors of each person, so the specific time of 1.2cmx0.9cm follicle ovulation, can not be generalized, there is obvious individual variability. Under normal circumstances, ovulation occurs when the follicle develops into a mature follicle. To summarize, it is recommended that women go to the hospital and work with their doctors to monitor the progress of their follicles with periodic ultrasound examinations.