Do "you" not want the child to live, or is it your husband pushing for it? Males sometimes get really territorial about "their" women having another man's baby. No offense, but that is why I'm asking. I've known men like that.
Are you really prepared to have your child pay the price for the crimes of the father? Is that just and fair? You answer that question for yourself. Remember, that *you* were the one that called it "this baby" and "the baby". So, you have a certain moral issue you need to consider. If you already see it as a "baby", then that could be a problem with your conscience, especially after you already abort him or her. You need to consider that now before it becomes a problem for your conscience after it's too late. That baby relies on you completely, no matter who the father is. She didn't ask to be there.
Are you sure it was rape? How do you know if you don't remember? And what if he drank a lot, too? Does it count as rape if you were both drunk out of your minds? How about if you freely consented while you were drunk? If he has feelings for you, does it really make sense that he would rape you? Is he generally a violent person? Is the person who chose him to "babysit" you trustworthy and a good judge of character? Consider the answers to these questions before jumping to conclusions. You are letting your fear take over. You don't even know whether you had sex! Also, take into account that you could be subjecting an innocent man to the social stigma of a rape accusation *if* he is not guilty of the crime. You don't remember. Always presume innocence until guilt is proven. That is the right thing and the fair thing (this is why laws in all free countries reflect that), despite his fight with your husband. The fight doesn't prove anything. I have a lot of sympathy for your situation. There is a possibility you were raped, but even if the baby turns out to be his, you just *don't know*.
It took me and my husband a year (actually a little over that, but I just say a "year" to save from explaining the details) until I got pregnant. Sometimes, it just takes that long. You are getting worked up over a coincidence. That, coupled with your husband's lack of objectivity (-because he fought the man previously, and the man already cast himself as your husband's adversary), means to me that your fears will only be enabled. You *both* will see things out of proportion to reality. I can't tell you not to get worked up about it as I'm not in your situation, but I can tell you as an outsider that - until you have actual solid evidence otherwise - you are worrying about shadows and sprites. Don't feel bad or "judged". If I were in your shoes, I might worry, too. I just hope I can provide some perspective.
Consult a doctor. Consult a lawyer. I'm sure there are ways of handling this, but it's such a delicate matter that I don't feel like it's my place to tell you too much. According to americanpregnancy.org, the earliest prenatal testing is 9 weeks. It's non-invasive, and there is no risk of miscarriage. I think, perhaps, if nothing else, you should get one done just for piece of mind. I think the baby is probably your husband's given everything you've said. :) But piece of mind is so important, and after you find out, you'll never have to think of it again. It might be worth the money you'll have to shell out for it just for that. Consult your doctor first and foremost, though - and sooner rather than later. You might feel a little better just knowing that you have taken some form of action.
(((please, try and get some sleep))))) And remember, that we're here for you at the first tri board. I know it's just the internet, but sometimes, it feels good just to let things off your chest.
I hope you find out that you've been worrying for nothing. :)
Oh, and if I were you, I would not provide this other man any *clue* you are suspicious, and don't announce your pregnancy to *anyone* yet until your suspicions clear, except to people that you *absolutely* trust and can confide in as to the situation. You don't want your pregnancy traveling to that man. If that other man is a rapist, you don't know what else he is capable of, esp. if he finds out your pregnant and is already possessive of you to begin with. If he isn't guilty, you don't want to start accusing an innocent person of something like this, either. Take care of yourself.