I slept on my bed without underwear with my cats, can the cats give germs to me when i sleep this way?

All of your skin surfaces are occasionally carrying various germs. You acquire these from the environment by contact or touch. Daily bathing removes some, but more are acquired as the day progresses, whether you wear clothing or not. The cats likely carry some different germs on their hair, ant these may transfer to you during this activity. As long as your skin is intact it is not a problem.