feeling guilty after one night stand

i had a one night stand last week and it was incredible but now i feel really bad about it. he messaged me out of the blue, we met up at this bar and before i knew it we were hooking up in my car right there. then we went back to his place for more. everything felt so spontaneous and intense but now im worried idont know him well enough to be that intimate or casual. is this normal? should i feel bad or just let it go?