Question on doctors notes for work

Ma
So I fell Tuesday and I hit my head but I didn't go to the er cuz I didn't black out I'm 22 weeks but the next day I had a sore back and chest pain but I called right after I fell Tuesday and they said they didn't need to see me so what do I do when the doctor won't give me a doctors excuse because they said I'd be fine since I landed on my back Butkus I was saying the next day I had a sore neck and chest pain but I didn't go in to the er