Ungrateful employer

25 weeks pregnant here and today I called in sick because of diarrhea. I hardly ever call in. I work with kids, I told my employer the truth that I dont know if it was from something I ate or if I caught a big and I dont want to potentially give it to my littles. She sounded very ungrateful that I called in. I for one if I was in her position I'm be glad that my employee was honest and doesn't want to gave it to the kids or other teachers. How would you feel? Do you think I'm over reacting?