No period blood?

Hi so I'm 15 I have gone through puberty I've had my period 3 random times over the past year and a half like regular with bleeding and cramps and all, but all the rest of the months there's been no bleeding, only period symptoms like cramps and diarrhea. I was wondering if this would be because of the medicine I take they are selexa, intuniv, latuda. Will birth control help regulate the bleeding? Thank you