Girls, hello everyone. My daughter has been spitting up after feeding …

Girls, hello everyone. My daughter has been spitting up after feeding for a few hours since yesterday (I didn't pay much attention because she always spits up excess, we also do reflux). Last night she spit up so much that I was in shock and called an ambulance. We were taken to the infectious ward where they told us to stay under observation. I refused. This morning she's spitting up again a little but often. And today I saw a yellow spot. We're going to see a doctor this afternoon and get bloodwork done. Has anyone had something like this happen?