Help! Some TMI

I last had my period Aug 5- Aug 9th. I am on a long distance relationship so we had sex unprotected Aug 10- Aug 16. According to app my ovulation day was Aug 19-20 during my ovulation I had no sex . However on Aug 20 i started spotting with small clots picture 1 - 2 days later pink spotting when I wipe. Today 8/24 picture 2 i experienced this when I wiped. Can someone advise? I have also been experiencing back pain and left pelvic pain sometimes painful.