This has really been bothering me so I decided I needed to ask some unbiased people.

I(20F) was starting a new job as a Barista in a small chain cafe. After my second shift(Tuesday) I fell ill with an intense cold that's been plaguing my household for about 2 weeks. My throat hurt, I was nauseated and snotty constantly. My next shift was scheduled for Friday(also my third shift) , I knew I would probably be better by then but regardless on Thursday morning I decided to let my boss know what was going on.

We talked on the phone, he said it may just be hay-fever and I said it definitely wasn't. I said I was still happy to come in the next day but just wanted to let him know what was going on. He said that calling in sick on my third shift was a bad impression, I said I wasn't calling in sick, I was just telling him I was sick. He said he was starting to reconsider employment and told me he would let me know that night(the night before I had to start early the next day).

I shoot him a text to tell him that I was 90% sure I would be well enough on Friday to come in but after reading all the informational packets he sent me I thought it would be better to let him know.

At around 6pm he sends me a message saying hes terminating my employment.

Now, I can see where he was coming from if I was actually calling in sick and wasn't sick. We talked on the phone so he should've been able to hear my strained voice.
He said it was a bad impression to call in sick (again wasn't actually calling in sick, just letting him know) but I feel it would've been worse if I showed up to work snotty and gross without telling him, especially because I work with food.

Tl;Dr. Wanted to let my new boss know I was sick. He fired me for leaving a bad impression.

Anyway, I came here to ask your opinions so let me have it.