What Causes Pinkish Vaginal Discharge After Unprotected Sex?

I had ended my period on Feb 24. I had a normal period and about a few days after it had ended had unprotected sex. Been off birth control for abut 2 months and my bf and I dont use protection. On Mar 5 noticed pink spotting. Next day when to the bathroom and wiped and found orange discharge. Ive had no cramps or pain what so ever and the spotting seems to very. Its not enought to soak a panty liner. What could this be?