1yr old fell and hit head on the cemented ground on friday. Sunday he is vomitting but not sick. Pls help what to do now? Is it bec he fell?

Forget alternative. This is a one year old. If something happened as that injury, and there are symptoms, for precaution, do not look for alternative causes of the symptoms. Go to your pediatrician, be evaluated, then you can find out the reason. Always point to the most possible cause as the cause, until proven otherwise.