My cats jump/stand/run on my stomach at times and it makes me nervous. Is this something I should be concerned about? I know they aren't doing it on purpose...its usually because I'm laying in bed and I happened to be in their path when they have a random spurt of energy. Lol they also love to cuddle/snuggle on my stomach, which is adorable ❤ I figured their weight on my stomach was fine in the beginning, but I'm 13 weeks now so I'm just wondering if this can harm my baby

Two of them weigh less than 10 pounds and one weighs 12 pounds.