Dear friend, There are chances of pregnancy , if you have had unprotected sex during the 10th to 25th day of your cycle. However the period can get delayed at times for various reasons which includes Change in sleeping rhythms, change in diet towards less nutrition, facing stress etc. Normally delayed period should come b 7-10 days of delay. The symptoms you describe are often there with delayed periods too, as psychologically the person starts feeling that she is pregnant. So you are on a critical point where you should get a home pregnancy test done and in case it is negative, you should visit a OBGYN person and confirm the things with an abdominal ultrasound scan. Avoid stress and anxiety and you may just get the period back! Dr Rakesh.