https://www.babycentre.co.uk/pregnancy/isitsafeto/nail-polish-expert/
Looks like no one really agrees on whether it's safe or not. I would think, using common sense, unless you're repainting your nails every day you should be fine. What about women who work in nail salons? Do they go on maternity leave as soon as they get pregnant? I doubt it, so it's probably a very very tiny risk.