Involuntarily pregnant ...!

I just wanted to get ready for work, when my stepbrother bursts into the bathroom .... because he actually starts to wank his cock on his sister, oh oh embarrassing. But when I saw his big part, I was also horny! He suddenly pushed me down and let me do it with my mouth. When he still wants to fuck without gum "No way!" .. do not even take the pill !! ... does not want to be pregnant by the jerk .... when I insisted on the rubber he pulled one over and fucked his sis hard by .... what happens then just before he squirts ??, he strips the condom and fucks on then he injected all his cum into me .... when I found out it was already too late! ! .. the sperm already flowed from my pussy. Should I take the risk and hope that he did not make me pregnant ??!