Whats wrong with my dog ?? :( pleeaaase help .?

My 8-9 month old dog has been sick all day, she vomited ( watery ) a few times and has been dry heaving allot.. she hasn't eaten all day and drank very little, i tried giving her water with a syringe.. shes also sleeping allot and is very weak, she has no interest in playing or her fave things... shes been in heat for almost 2 weeks could this be why?