Okay, so on July 30th I lost my virginity and yes, we used a condom and no, it did not break. I have not had sex since then either. I started my period the next day, July 31st, when it wasn't due until August 6th. That period ended August 4th. I re-adjusted my period schedule (My Days-IPhone) based on my most frequent period, which was the one from the 31st through the 4th that I previously mentioned. It changed the prediction for my next period from sometime in September to August 22nd. It is now the 28th and my period has still not come. But I was sick with the cold from about August 4th through the 12th. Then I got a cold sore right after and that stressed me out because I was about to leave for vacation. I'm from Ohio and my family took a plane to California on the 18th of August and then another plane back on the 26th of August. My period is usually pretty regular even with being 16 years of age. Can any of these factors play a role in a late menstrual cycle? A friend told me that because I started my period the day after losing my virginity, that I couldn't be pregnant. But isn't that too early for the body to register a pregnancy and start to change for it? I'm just stressing out a little over it, so any help would be great. Thanks!