<s>[INST] Hello doctor ,my follicular study report on 11th day is 20*15mm ,endo 3mm.When will it ovulate?Thanks for your reply in advance. [/INST] Welcome to Healthcare Magic This is the right size for the follicle to rupture and cause ovulation. It can happen any day from now. It is better to do ultrasound follow up to find out when it has ovulated. You can start having sex from the day ovulation is seen till 2-3 days after that. </s>