Irregular

I’ve never had a regular period. When I was younger we thought it was due to the medicine I was on for adhd but I am no longer taking the medicine and am still irregular. I usually have one period every two or three months. But these last two months I’ve been more like spotting with intense cramps. My flow hasn’t even been enough for panty liners and I’ve never done this before, it’s usually very heavy. I haven’t had sex in 3 months and I’ve taken several pregnancy tests, all negative. I have never been to a gyno since I have no insurance and cannot afford it. So any advice would be appreciated.