I don't recommend it, but I was staining trim when I was pregnant with our first child. A little makeup is not going to do any damage if the stain didn't
Seriously, why do we worry so much now? Women use to work up until birth and they didn't think so much about what to eat or wear or look at. Granted, there has always been some that had those superstitions, but on the whole women have just been getting pregnant and having babies.
If you want (or need

) to wear makeup, wear it. If you are worried, then don't. That's simple, but it's the way I try to face everything.