How long should i watch my 11 week old for symptoms after exposure to strep bacteria?

Depends on the disea: If your concern is strep b exposure around delivery the venerable period is past. We usually see issues arise in an early <1wk or late (2-4wk) pattern with this germ. Every day further from delivery without a problem means its rarely if ever seen. If you are concerned about strep a, that throat germ is not as quick or deadly & often produces only a cloudy nasal discharge at that age.