Period 4 months late??

So I am NOT sexually active, & I've had my period since the 6th grade. (I am in 9th now) it used to be really regular, but now it's about every 3-4months?!? The only medicines I'm on is my depression medicine, & I've been on that for a while. Idk what to do, it worries me even though I'm a virgin 😂😂 thoughts?!?