I understand Starsky's point about the STDs...and the testing.
I could be wrong, but I don't think it's necessary in your situation.
It's YOUR LIFE and I don't want to advise you to be dangerous, but for ME if I were in your shoes
I'd find it depressing but I don't know your h.
I'm sorry, 25, but this is possibly the most grossly irresponsible thing I've read on here in a long time. When it comes to being medically safe, when a spouse has had an active affair, whether or not it's "depressing" is really no concern to me, nor should it be to anyone. If Bestgal has any doubts about this, she should ask her OB/GYN, and follow their advice. I'm really not advising anything that a good doctor wouldn't also recommend.
Besgal, I want to caution you in that you're trusting that your husband is telling you the truth right now. HE HAS ALREADY LIED TO YOU, and when people get caught up in affairs, they LIE -- period.
Now is no time to operate based on your FEELINGS. Do what your HEAD tells you is the right thing to do, and do some research about infidelity. You are projecting onto your husband your own values, and he's simply not in the same place right now.