I'm 22 years old. My cycle is usually 28 days, give a take a day or 2. My last period was on Nov. 19th. My boyfriend and I had unprotected sex on the 6th. He pulled out before anything happened. My period was supposed to start on Dec. 16th. It has yet to start. This is not normal for me and it's never been this late. I took a pregnancy test on Dec 18th and it was negative. I plan on taking another one once it hits the 1 week mark. I have no pregnancy symptoms. I'm a little bloated, but that's normal for me when my period's about to start. To say I'm a little stressed is an understatement. I've been super stressed this whole month really, more stressed than I've ever been before, but I've never noticed stress or sickness to really affect my menstrual cycle before, so I don't know if that could be what's affecting it. Some advice please!