Fertility help


My fiancé and I have been trying to conceive for a little over a year now. I have a 4 year old little boy already :) I have been taking prenatals, and have used the ovulation predictor kit this whole time. It will tell me when I’m ovulating and we have sex at all the right times but still no luck.. can anyone give me some insight on some over the counter medicine that can help me ovulate? Thanks..