I Am Over A Week Late On My Depo Shoot,

I am over a week late on my depo shoot, I will be going to the doctor Friday, but, now last week, but the week before I had a full period. Bright red blood, lasted a week and all. I have been very sexually active the whole time, I have also felt a pricking type feelings where my uterus is and on the right side for two days, is it possible to become pregnant that fast when you miss a depo shot?