What Causes Delayed Periods With Abdominal Cramps And Clear Vaginal Discharge?

I did unprotected sex on 6th dec 2014 two days before my expected periods on 8th dec...to be safe i took an ipill right after two hours of incident..i got my normal periods on 10th dec..now on 16th jan i m waiting for my periods..i having lower body pain frm last three days...with some excretion frm my vagina..i m worried can i be pregnent...i had no intercourse after 6th dec...