Urinate tract infection?

I’ve been having lower abdominal soreness for a few days now/ gas / sometimes sharp pains in private area / and lower back pain and sometimes pain in my middle and upper back. My bladder feels full but I’m not having problems peeing and there’s no burning. I don’t have to keep going to the bathroom. Could this be a UTI? I also had painful sex a week ago and that’s when this all started.