Hi I'm 17 Years Old And I've Been With My

Hi I'm 17 years old and I've been with my boyfriend for 3 years we always use protection when we have sex. My period was regular until I stopped for 3 months then it came back and I had big blood clots and was heavy so I got on the pill I had to get off the pill do to family issues( I didn't have insurance) it was regular for a year after that then all the sudden skipped 4 months of my period, I had big blood clots & really heavy at times or reallly light, my periods never really go away. I will bleed for an hour one day skip a couple days then bleed for a day. It's just irregular. I'm afraid to go to a gynecologist, but I really need to. Can you give me an idea of what's going on with my body?