Can you get pregnant from pre-cum

We've looked all over the internet, some say yes, some no, and some say maybe, so we are a little unsure. What are your opinions on it, she thinks she's showing signs, feeling sick with smells of food, always tired, no cravings yet but she is eating a lot more than usual, I said she needs to go to the Dr, but she's a high pregnancy risk and she doesn't want to get her own hopes up. Idknshe doesn't really talk much about it but I'm curious myself...