It's bad to see a snake any time... those slithery, scaly, creepy, sometimes poisonous, always scary, creatures. On the other hand, if you see the snake, you know where it is. If you don't see it, you're constantly wondering where it went. Being pregnant doesn't make a difference, except that you're radiating more heat, from a bigger body, and can't run as fast... no, let's not think about that.