I'M SO SCARED

So, I had sex for the first time a week ago whilst I was on my period. I bled quite a bit but I expected it. I wasn't expecting it so we didn't use any protection (stupid I know). I went and got emergency contraception the next day. A few days later we had sex again (protected this time, Learnt my lesson from last time). I bled again and I'd definitely finished my period. I haven't had sex since and I've just randomly started bleeding tonight. I've also got what feels like period pain.
Has anyone else had this?
Is it a side effect of the emergency contraception?
I'm so desperate for some advice. Please please please help me. I'm so scared and I don't know what to do😩