lower left pain?

I am having lower left sharp pains? i believe it might be where my ovaries are but the pain started yesterday and it just started hurting more as i was masturbating? i looked it up and it says it could be an ovarian cyst but i honestly have no idea what that is or how i could’ve gotten it. i got on nexplanon in october… could that be it? i’m also going through a slight pregnancy scare (i know i’m on birth control i’m just an anxious person) but this isn’t a sign of pregnancy right? help!!