Stay at home dads?

We're pregnant with baby 3, not intentionally. But every baby is a blessing so we're excited, naturally. I've worked and re-worked our budget, there's no way there's an extra 900 floating around in there to put another kid in daycare. We're discussing the option for my husband to stay home. My dad and I run a small business together and there's no option for me to stay home. The only thing is that my husband carries the health insurance for us, there's pros and cons of owning your own business. Health insurance is one of them because it's so expensive. He can referee hockey and he's an accountant so I'm sure he can find bookkeeping gigs on the side. Is there anyone in a similar situation? Advice?