Confused

I was on birth control to regulate my period because I never got it otherwise. I was on it for about six months before I had to stop due to not being able to afford to go back to my doctor. And about two months ago, I didn’t get my period or the month afterward, and I was still taking my pills because I had them still. I just ran out of them and I’ve had some cramping for the past couple of days and my lower back and sides have ached severely. To the point that it feels like I’m being stabbed. I’m just really confused lmfao