I got the depo shot about 3 weeks ago. Due to the fact that I had an abortion, they gave me it once the surgery was done.. I bled for 3 weeks and I just stopped bleeding about a week ago.. I just now spotted I think and it s bright red and a little dark.. I had unprotected sex last week, but I didn t use Plan B because I m on depo.. I have little back pains too, I m a little nauseous. Am I pregnant? This is my first time using the Depo shot so I m very confused.. Please help, thanks so much.