How long are you contagious with strep after you have started taking amoxicillin?

Generally 24 hours. Once on the antibiotic for 24 hours is typically when schools allow students to go back to class, but i would also recommend reducing your exposure to others until the fever is gone and you start to feel better.
Depends. The general rule is 24 hours for public exposure. However, you might want to avoid deep smooching with your spouse & family members for a few days to be sure.