What Could Blood Discharge Post Sex Suggest?

hi..i would like to ask if there's a possibility that i am pregnant at this very moment..I took my 1st contraceptive pill last Feb. 12 and has taken it diligently..but then on my 3rd day since i took the pill, i made love with my husband without condom....i didn't have my menstruation till now March 8 but then, after our lovemaking last night, i saw blood streak in my discharge...i'm confused...please tell me about it..thanks