need some help ladies!

Alright so a few weeks ago me and my guy were going at it and the condom broke. He had not cummed yet, but he made me take a plan b anyways because we are so not ready for a baby! Anyways, a week after I took the plan b I started a very light bleeding which got heavier over the next few days. The bleeding has lasted over 8 days now and is heavy enough that it flows, and I have to wear a pad but I never fill it up. My period is 1 day late. I also just started the depo shot a few days ago. I talked to my doctor and she said that if it was flowing that she was giving me the shot. I'm still not sure what is causing the bleeding. Do y'all think it is from the plan b or the depo shot? Thank you ladies so much for your responses 😊😊