Birth control?

I got the depo provara shot. Then the next day had unprotected sex. Now my periods late. I know the shot messes with that of course (I was on it for a little less than a year before). I've felt like I've been pmsing minus cramping for a bit too but it feels different. I'm 19 now and it wouldn't be the end of the world but it'd still be best if I wasn't.

(And he did cum in me.)