I'm terrified

I was sexually assaulted around the same time I got pregnant by my fiancé. I was never penetrated by the perpetrator but he did rub his bare penis on my private area. I'm not sure if he had ejaculated but 3 weeks later I found myself pregnant. My fiancé had sex the morning before I was assaulted. I'm currently 5 months pregnant and my anxiety has been through the roof with worry. Is it possible that this man who violated me has gotten me pregnant? I'm starting to regret keeping this from my fiancé and family especially since it's getting closer to my due date.