What are my chances?

R.

My period was from June 22nd-27th and on July 2nd I went to the doctor and got the depo shot for the 1st time. During that time, I was in the 3rd day of my fertile window (which is the highest day to become pregnant). My partner and I had unprotected sex that following night; July 3rd and obviously he finished inside me. I’m not sure if the depo shot kicked in immediately or is there a chance I may become pregnant?