Help please

We took our girl to the doctor today and they said nothing seems to be wrong. I’m still worried but husband says I’m overreacting. These are her symptoms, what do you think? She is nearly 8 months old.

She’s been fussy and moody for a week now. We wrote it off as teething because her upper gums look swollen. Last night she projectile vomited. Today she had 2 green diapers (mucusy). She hardly ever gets diaper rash, but tonight she has it pretty bad. There are some red spots on her cheek and chin. She was very fussy going to bed tonight, but she eventually fell asleep.

The doc told us she’s probably recovering from a stomach bug. Does that sound right? Could it be teething?