Question: Really bad hives…worried Doctor made a random guess

i have been getting really bad hives that burn on and off since friday night. i feel very tired and week. I went to the doctor today and he told me i have TSS from wearing tampons last week during my period. I looked at the symptoms of TSS and i don’t have them. i didn’t have a rash, i had full on hives. i didn’t have a fever, i wasn’t vomiting and didn’t have diarrhea. i have never had hives before. i don’t have any known allergies, and i have not changed detergents or anything like that. i am very worried that this was just a random guess. is it possible that this is accurate? the nurse thought it was odd as well. They gave me shot and he wrote me a prescription. please help