Kate - hun I completely understnad not telling DH. I'm sorry but I agree I would rather live with the guilt myself then to destroy everything else around both families - I would be making sure the other guy in question is just as adament as you are though. Probably another unpopular choice also but I wouldn't be telling the other guy about the pregnancy. I know he has as much rights etc but it could seriously complicate the situation if he feels strongly about children now or in the future.

Have you got any previous cycle history to go on as for how long after you get your OPK that you ovulate - lutel phase length or anything. I hope your dr can help you but as another poster said ovulation and fertilisation is so unpredictable. My heart goes out to you.