Signs if you’re pregnant

I heard that a sign that you’re pregnant is that your pet will follow you around and just be more protective. I also heard a sign that you’re pregnant is that your boobs with be more veiny and larger. If none of these happen does that mean you’re not pregnant? Also, does it matter if it would be their first pregnancy?

This question might be dumb but I’ve heard it so often so I want to know if its true.