Depo Provera

Okay so I’m on the depo-provera shot and today was my shot day (my third time taking it) and for the past week I’ve been bleeding really lightly and it’s been kinda brown like old blood but sometimes bright red, it’s been going on for like a week and a half but very very light. Anyway, I had unprotected sex this morning not knowing it was the day of my shot and I’m kinda worried about the probability of me getting pregnant from that just because it was my shot day, and the fact that last time I got the shot I flexed the muscle in my arm wrong and a little bit came out, not a lot but some, and the fact that I’ve had this little baby period for the first time since I got on the shot. I just need a some help figuring this shit out😂