Trouble conceiving baby number 2

My DH and I have a 4 year old. We have been ttc for almost a year now, the one thing I thought might be the problem is my husband is on Lexapro 10mg. But I checked with the doctor and he said it should have no effect on his sperm. We have no problem trying it’s just getting very hard to keep getting my period every month. I want this so badly. I have tried preseed and I have check when I ovulate. I don’t know what else to think. Anyone have any tips?