Date wise, you have no issues if your early ultrasound (and seventh week is plenty early) said August 20. It sounds like the issue is the tendency to anxiety, and not the false scenarios that the anxiety invents. Congratulations to you and your husband on your wonderful child.
Annie
Thank you so much for your response, we did kick that guy out as soon as we found out we were expecting. I do have a generalized anxiety disorder that makes me worry about unrealistic scenarios (yes even toilet seats) and when you included that in your response it did make me realize that it is my anxiety that is causing the worry. I had an ultrasound bi weekly beginning January 5th 2012 which would have put me between 7-8 weeks gestational and they gave me a due date of August 20th. I was studying the ultrasound from January 5th and although I don't know what most of it means I did see a measurement of 16mm on there, if that was the crown rump length it would have put me right at conceiving on November 28th when I should have so I'm hoping that's what the actual measurement was and not like an estimation or something they had plugged in already as like an average or something.
Well, in terms of a DNA test, I don't think I would waste the money.
First of all, I would bet you washed your hands. Why would anyone walk around with an attempted rapist's liquids on their hands after such an unpleasant event? (I assume this guy is long ago thrown out of your house, by the way.) You have to trust yourself, if you noticed liquid on your hands after the shock of the moment was over, you would have gone to wash off, with grimaces of disgust.
Second, there probably wasn't any sperm. Pre-ejaculate by itself does not contain sperm. He would have to have ejaculated recently and have some residual sperm left in his urethra, for there to be any. Sperm dies when exposed to air. if your hands were no longer wet with whatever he had on himself (probably likely to be sweat, but even if it was pre-ejaculate and even if it contained sperm), you would not have gotten any on yourself. And it is not like you rushed off and put your fingers directly into your vagina in any case, you only 'might' have later on gone to the bathroom.
We get a guy in another forum who writes questions involving imaginative scenarios involving masturbating and drying off with a towel or sometimes possibly getting something on the toilet seat and then a female relative (usually his sister but sometimes his mother) being in danger of getting pregnant. Sperm is just not that mighty, no matter how mighty he would like his sperm to be. I mention this because I want you to see that indestructible-sperm scenarios are really not true.
If you have your very earliest ultrasound, what due date did they give you for your daughter based on it? We can always check that and confirm that she came from your mid-cycle ovulation, if your ultrasound was early enough (like 7th or 8th week of pregnancy). If so, write back with her estimated due date.
You could (if you had to) do a DNA test by swabbing a glass from which your husband has drunk something, I have heard. Those drugstore tests are only considered moderately reliable, and if your husband ever saw a DNA test lying around that would be the end of his trust, so I don't recommend it, but I think it is possible if it would help you.
Finally, though, you really have to accept that the strongest likelihood is that you are processing the ugly incident with the guy, and have focused on worrying about paternity as an easier thing than dealing with the big anxiety caused by the event, the fact that you didn't say anything, the fact that this guy is still around, and so forth. It might be that even a DNA test wouldn't convince you because you would still be stressed over what had happened, not because you seriously doubted that your husband is the father. In your shoes, I would work on the anxiety and what all of this (and your reaction) says about you and your life, and go from there. I would tell my husband what happened, if he would believe me. One thing you can take off your plate is the worry that by touching a guy's penis you got pregnant by him.
ALao a DNA test really isn't an option right now because I don't want to freak my husband out, and I don't want to get that idiot who caused this mess in the first place all started up.