It can be dangerous to swallow too much toothpaste.
However if you happen to swallow a tiny put of toothpaste or swallow the small amount of toothpaste that you use for brushing your teeth then nothing bad should happen.
I have swallowed some toothpaste before and the worst that happened to me was I got a stomach ache for a day until the toothpaste left my stomach.
You can get fluoride poisoning though if you do swallow too much toothpaste so just do your best to avoid swallowing toothpaste.
Swallowing toothpaste could make you sick and it's not meant to be swallowed.
Make sure you teach your kids if you have any to spit out toothpaste and not swallow it and always supervise kids under 7 years old with brushing their teeth to make sure they don't swallow the toothpaste.