Hello,
I am sorry your kitten is not feeling well. He will need to be seen by a vet IMMEDIATELY, and since it is the weekend you may need to have him seen by an emergency vet. When such a young kitten begins to vomit clear fluid or foam it means that the stomach is empty. The continued vomiting typically points to an obstruction, which means that this ktten probably ingested something while exploring or playing. Because your kitten is so young, the repeated vomiting will debilitate him extremely quickly, and while he continues to be nauseated and vomit, he cannot take in any food or water to sustain himself. This will quickly add up to disaster, and the longer you wait to have him seen, the more difficult and expensive it will be to make him well. Time is of the essence because he is so young and does not have the strength and reserves that an older, larger kitty would have. Please have your kitty seen today by an emergency vet if you cannot get an appointment with your regular vet, and let me know if I can be of further assistance. If this has been helpful, please hit the green accept button. Best of luck with your handsome man, I hope he feels better soon :)
Emergency Critical Care Nurse
16+ years of veterinary experience