Check ur ovulation cycle if u r having intercourse according to that. Counting from 3rd day of ur period on 9th day u shud hav sex every day or alternate days for 7-10 days. If Ur periods r regular and normal 28 days cycle then try it.

Are you pregnant? Or want to be pregnant? If you are not getting pregnant then I wil suggest to visit a good gynaecologist. She will do the check ups and let you know what the issue is