What if my baby gets a stomach bug?

I hope this isn't a dumb question but my 9.5 month old son may have been exposed to a stomach bug this morning: my child care provider's son threw up so hubby picked our LO up. If he starts throwing up do I still try to breastfeed periodically? For an older child i wouldn't give food or liquids... I have a call in to the doctor and am waiting for a call back but figured someone here might have good advice. (Btw, provider's son is feeling better now.)