Prometrium is a synthetic progesterone that prevents endometrial hyperplasia and can be used to prepare the endometrium for pregnancy. Although Prometrium can cause anaphylactic reactions in those allergic to the drug, the symptoms you are describing are not part of the side effect profile of the drug.
However, your symptoms are serious and warrant immediate medical evaluation. Your symptoms could be due to an allergic reaction or a drug interaction. You should call and schedule an appointment with the doctor who prescribed you the Prometrium and be evaluated immediately.