Can I get a girl pregnant without ?

I had everything but ual with this girl I know and now she is pregnant. She is 6 months and the dates seem to coincide. She sais she always wears condoms with her husband and that she can't be pregnant from him unless a condom failed. When I had relations with her I shot my load around her l area. Exterior l area. Could she have gotten pregnant from that or is a failed condom more of a possibility for pregnancy?