I had unprotected sex on 23rd of November and took unwanted 72 1.5hrs after it on empty stomach. I did not vomit. However a week later i.e. on 29th November I started having brown vaginal discharge with minor cramps. Is this normal?  My last menstrual cycle was from 15-21 Nov. I get my period a day or two late which means I'm next due on December 15. But now i am experiencing this brown discharge... Does this by any means imply that I am pregnant? How long will this last and how does this effect my menstrual cycle?