So me and my girlfriend had sex for the first time a few weeks back. It was on the day she was supposed to start her period. Since that day she hasn't started and it's been about two weeks now. She has been stressed, we think that might be the cause of it but we are still worried. We used a condom and it did not break. She has a very regular cycle and isn't usually late. Is there any room for concern, is it likely she could be pregnant? She shows no signs of early pregnancy but is having PMS and cramping. Any advice?