I dont know if i am infertile. I dont get regular periods, maybe 2 a year. What tests can help me find out?

I have never had a normal menstral cycle unless i am on birth control (BC). since my husband and i got together, i havent used BC or condoms, and that been 4 years now and i still cant get pregnant. I had a HSG done about a year and a half ago and the doc said everything looked normal. Does that mean i have eggs or not? this is so frustrating. i dont know what to do.