Infant head injuries

Anyone experience a head injury with their infant? I was being a super smart mom (🙄) and filming our almost 6 month old standing in her crib when she fell backwards and landed on the mattress, smacking the back of her head into the headboard on the way around 11 am. She cried for a few seconds, was her usual self the rest of the day until about 9 pm when she puked so many times in a row that only yellow bile came up. The hospital was super happy with her vital signs and did no scans or X-rays and she even nursed a few hours after and has been nursing the usual amount/frequency and keeping it down. Anyone experience such a delayed reaction with a “mild concussion”? She had no fever or diarrhea so it’s hard to believe it’s a stomach bug and no one that’s held her is/was sick either. Thank you in advance from a not-so smart mom. This Sophia: