Me and my boyfriend had sex about a week before my period and I Take the Depo Shot and he had a condom on and we didn't see any cum outside of the condom but he pulled out and chummed outside of me but still had condom on.. BUT we had a towel under us and he layed on me for a min and then when he got up I used the towel to wash off my self then when I was finished washing off I went straight to the bathroom to pee.. What is the chance of me being pregnant ?