It might wake your baby up bit that's about it
I went hunting and target practicing for a lot of my pregnancy and it didn't effect my baby aside from waking him up. I talked to my doc and she said it wasn't a problem.
Let's just say that bullets have lead in them, and we no longer use lead in paint because it is toxic.
There is nothing to worry about!! I deer hunted with my other pregnancies. And ^^ there are small amounts of lead in bullets! My dad is a gun Smith.. and I hunt every fall pregnant or not!