Can Nausea, Vomiting And Diarrhea In Child Cause Rheumatic Fever?

my 13 month old had nausea vomiting and diarrhea last week, he was taken to his doctor on day 3 and we were told he had a virus. He finally stopped his intermittent vomiting and diarrhea on day 5. During his sickness, on day 2, we had friends over and shortly after my friends son seemed to catch what my child had. His illness has lasted 5 days as well and was taken to a physician today and diagnosed with strep throat. Upon hearing this I took my son back to the doctor for a strep test, even though he now has no symptoms. My son tested negative(rapid test) My concern now is that we re 9 days out from onset of symptoms, could he have had strep, is now testing negative, and is at risk of rheumatic fever or other complications.