OMG – Pregnant by my girlfriend's boyfriend!

My girlfriend and I wanted to have a really nice girls' night out again. She went out to buy something to nibble on, so I quickly jumped in the shower with her. Without warning, my girlfriend's boyfriend came into the bathroom and absolutely wanted to get into the shower with me. Unbelievable, he didn't care about his girlfriend at all. Since I was so horny too, it just happened! But the idiot came inside me without saying anything. What a bummer, I don't take the pill and now I can only hope that nothing happened. Would you have just injected me too?