I feel so awful 😢😢

OMG! I feel so terrible😢😭. So I was carrying around my 3 and half month old son & he likes to move a lot in my arms. Look around etc. Well behind us was the bathroom door & I backed up a little & at that moment he tilted back a little & he bumped his little head on it 😢😢. He cried for a second then stopped & was all giggly again. Left no mark no nothing. It wasn't a hard hit at all, but I feel so awful😢😢😢