What Causes White Vaginal Discharge After Coming Off Depo Shots?

Ive been off the depo shot for 1month now, i was only on it 6months. ive had unprotected sex last week and 3 days ago i had some pinkish blood on my pans then it was brown it wasnt heavy and it only lasted for 3 days, now i have white discharge i dont know whats going on , could i be pregnant??