What Causes Reddish Vaginal Discharge After Taking I-pill Followed By Sex?

hi.. i had sex wit my bf on the 7th day from my 1st day of periods.. i took an i pill within 36hrs just to be safe.. a week later i have slight vaginal bleeding n reddish discharge like the one we get during normal periods.. is this the side effect of the pill or something else.. is it normal..? should i consult a gynecologist