Trying To Conceive Unsuccessfully, Delayed Periods, Severe Pain In Uterus During Intercourse. Causes For Infertility?

hi, I am trying to get pregnant from last 8 months, but I couldn t get pregnant but this month my menstrual cycle was late, so I think this time i will surely get pregnant, i did a pregnancy test but it shows no pregnancy.... One more thing I want to consult I feel a sever pain during intercourse on a specific point, on right side of my uterus ...so from all this information can you suggest me what could be the causes of my infertility?