Infections

Okay I had sex over a month ago and when I did it was very sore and uncomforatable , after that it was sore and had some sort of discharge all over when I woke up for weeks until my period ,my period was very bad , heavy flow and lots of pain and this doesn't usually happen to me , I finally came off my period on Wednesday and ever since it burns when I wee and I feel like I really need to go and when I do not a lot comes out .can anyone tell me what it could be .