I'm waiting for this to show up on Lifetime.

Yes, it's possible, it's called embryo donation and a pretty common procedure. Although it has many different methods, and the technique of taking an already fertilized egg out of the mother and implanting it into another woman is not one that is widely used. Doing something like that seems like a lot of work and personal health risk to cover up a cheating scandal, especially for an unfaithful husband and his mistress.

Wouldn't they need to take the fertilized egg out the second it happens so it doesn't implant?

Not necessarily, implantation doesn't happen until day 8-9. So the embryo is usually removed between days 1-2 after fertilization, although, you can wait up to 5-6 until the blastocyst stage to remove it. That's the problem with the son's story too though, you can't really detect a fertilized egg that hasn't reached the uterus yet, not without strict monitoring, which isn't usually done after an affair. In order to know that a woman is pregnant, the embryo needs to be implanted already. By that time it's too late to remove it for the embryo donation procedure.

It doesn't say he's a child? He could be 35 tripping on some drugs or something. Also I don't think saying "bless you" to be polite is equal to conspiracy theories. :/

what?..

I want whatever you're taking because it must be some really good shit