I'm Having Severe Tummy Pains I Recently Got The Contraception

I'm having severe tummy pains I recently got the contraception injection in my butt and have bled since I got it but in the past week it seems to have ceased but attempting to get intimate with my partner it happens again I've also recently tried to overdose on prescription medicines with a can of coke and had my system flushed could this contribute to the severe tummy pain