Hi, my boyfriend and I had sex on October 24, and this is the second time we had sex. He used a Trojan condom the whole time and did not ejaculate inside of me. I was a week or so late the first time I had sex which was on September 20th. I received my period soon after on October 4th. My periods are never truly regular, but I will be two weeks late on the schedule following last month of October 4th. I took a First Response about a week and a half ago and it said negative. I am just worried as to why my period is so late. Is it due to my body changing due to sex? I am sixteen and I do not know what I should proceed to do. It seems impossible that I could be pregnant due to our precaution. My boyfriend filled up the condom afterwards to make sure it didn t break, and it did not.