First I would like to say congratulations on the pregnancy!
Second, I would like to say how sorry I am that you had to go though such a horrible experience, only to cause you this much stress in a time that should be filled with so many other stresses.
Ok, was the incident reported? If so, in cases like this, the state may pay for an early paternity tests. There are risks involved. Only you know how you would feel and handle the results. I also think that counseling might be something to look into.
Are your doctors aware of the situation? If so, what is there opinion?
We are here for you if you need to talk about anything. It doesn't have to be pregnancy related, even though in this case it is. PM me if you want to talk.