Slightly spoiled milk

Katherine

My just turned one year old had a eight ounce bottle this morning. I had just open the gallon of milk. He drank it started feeling sick couple hours later. It dawned on me about two hours ago it was the milk. It smelled off and tasted off. He has no fever. Vomited multiple times and tired. Should I contact pediatrician. Some things online saying bacteria could be bad to call. Something’s say wait it out. He is sipping on pedialyte now

Thanks in advance