What Causes Vaginal Bleeding After Intercourse And Delayed Periods?

Hi so my first time having sex was either the end of May or the first week of June so then I went to Disney world the last week in June 24th-29th do I was a little worry about if my period was going to come on because it was unprotected sex there were no bleeding after the sex and my period came on 28th night or June 29th morning I couldn t remember because I was on vacation but I remember between The beginning 2 weeks of June we had Anal sex and I started bleeding but I found out I was okay then I Had Sex again July 13 but it was protected this time and he didn t nutted so afterwards I noticed bleeding it wasn t a lot it stopped so it didn t last over a day and so it s been 2 weeks after sex and my period was suppose to come on either the 28th or the 29th but its the 30th Friday the 28th I had cramps but I wasn t bleeding now I m scared I know I m like 2 or 3 days late but I m still worried please help !!!! I very scared