Should i ask my mom if i can go on birth control?

Okay so i first got my period at 9, it wasn’t regular. I lost my virginity at 14 and still my period never became normal. I’m 17 and i still miss MONTHSSS

I don’t want my mom to think I’m having sex, so i don’t know what to tell her or how to ask

She doesn’t really know about my irregular period either

And i don’t want the birth control because I’m having sex, i want it because i really want my period to be on track. It’s super annoying missing 2-3 months and then when it comes, it comes all at once. And then it’ll go “normal” for maybe 2-3 months and then i probably won’t see it agin for a while.

HELP!!!