Hello Thanks for writing to us with your health concern. Let me answer your questions one by one. 1. Normally in a 28 day cycle, ovulation occurs ( or the egg ruptures ) on the 14th day, that is midcycle. For ovulation to occur, the follicle size should be atleast 18 - 22 mm. SO in your case, on day 17, the size is nearing that which is optimum for ovulation. I would not call it normal, because ovulation is slightly delayed. If you have a history of delayed cycles, then this can be considered normal. 2. Normally ovulation occurs by itself, without an external trigger. In some conditions such as PCOS _ polycystic ovarian syndrome, there is need for artificially inducing ovulation through medication. Triggering ovulation by an injection does not increase the odds of conception, but ovulation if observed, means that there is a good chance for you to get pregnant if you remain sexually active around the time of ovulation. This is true provided your fallopian tubes are intact ( open ) and your husband s semen analysis is normal. After the injection, the egg gets ruptured within 36 hours. 3. Once ovulation is confirmed, you should remain sexually active for 3- 5 days following the documented ovulation. Take regular folic acid tablets. All the best. Take care.