That does complicate things. I guess wait and see how a repeat test comes out.
I was going to respond to "can't move out for financial reasons". I don't believe that's true. You don't want him to be put in a hurtbag is what you mean. I'd talk to your lawyer about your legal right to have him leave (and set up him paying c.s. etc). What he is doing with his blatant affair is emotional abuse. It's basically, "I can screw this OW anytime I want and there is nothing you can do about it".
Since you may be pregnant (and I'll withhold judgement on him staying to work on the marriage if that's true), I'd just do nothing drastic for now. I would get more space from him. Maybe leave him at home while you go out.
In the end, it's not the years in your life that count. It's the life in your years. Abraham Lincoln
It is hard to fail, but it is worse never to have tried to succeed. Theodore Roosevelt
