Could I be barren?

So I started getting my period at about 14. I never missed it same day same length. I lost my virginity at 18 but in the summer. Come October I don't have my period. I go to the doc says that's normal gives me birth control to get period says birth control will help with cramps. Tried it . Gives me my period but it's now extremely painful and the lightest flow. Ever like just spotting and it last super long . So I stop taking it and it doesn't come again until I take it again. This has been happening for over a year . I also get hot flashes a lot and have some menopausal symptoms . Am I crazy or could something be wrong with me ? Did anyone else go through this and find out they can't have babies or what . They've checked for cancer last year and I'm good .