I thought that was part of the side effects of the pills

To whoever that may help me, I am 17 years old and I've started having protected sex with my bf but he would only last 2 minutes. We would go for a second try and it'll still be the same time . I got my period twice on May, one was on may 8-may 13, my second period was May 27-the end of the month .None in the month of June, I also started on birth control pills on July 7. The clinic told me to use condoms for atleast a week, 4 days after which is a Wednesday July 10 we had our first unprotected sex. I still didn't get my period . I would get nausea and dizzy all the time with sore breasts but I thought that was part of the side effects of the pills . Would that be a reason for it?