Toddler sick

My 3 year son had a cough about a week ago it went away just in time for him to start a runny nose and his cough back up...but tonight he started throwing up. He has throwing up 3 times in an hr and heaved once into the 2nd he bc he has nothing left. His breathing has been fast but as I'm typing this his breathing is slowing down but not to normal and I'm trying my best not to go online. I know your suppose to look for discoloring in the hands and lips...his fingers look great...his lips just kinda look dry they arent discolored I dont think. He hasnt had really a temp. He has a doctor app at noon I'm just wondering if I should take him to the er or just wait...hes sleeping right now.