Nena, first of all, relax. Yes, you may be reacting, but if you just be patient and keep watching your symptoms, you will probably have time to deal with them if you need to. If you're concerned, certainly call the doctor, but I think you have a little time to relax.
When I reacted, I felt horrible for days, and then I started getting a bad headache and a very sore throat, and then about 12 hours later I started to develop the rash, went to the hospital and was laughed at and told that there was nothing wrong and sent home, and *then*, twelve hours later, the more severe rashes began, and it was another 8 hours after that before the disabling joint pain set in. I was in hospital by that stage, sent there by my doctor.
What I'm trying to say is that a reaction can develop gradually - it did for me, anyway - and that you may have time to deal with your symptoms if they do turn into a more severe reraction.
Another thing that might help is to take an antihystamine, if you're allowed.
Hang in there,
Co-Moderator Crohn's Forum.