Hello Thank You For Reading This Question.I Am Concerned About

Hello thank you for reading this question.I am concerned about being pregnant. I've been on birth control for about a month already.I had protected sex while I was on my period,about 3 weeks before my next period I had seen a small spot of white/pink creamy discharge and a few small drops of blood that same time.After this I had no more discharge or drops of blood, it has now been 10 days and my period was supposed to come two days ago . what could it be?