Mordern Medicine Worries

Today Rebecca has a check up at the doctor's office. I am a little worried about taking her in.
In the last 6 months she has had an allergic reaction to ammoxiciillin, bug spray, and sunscreen, and after her MMR shot came down with rubella and a few months later the measles. She did seem to handle the flu shot just fine, though. Do I dare try her on the rest this time? She has been so very cranky the last two days, i am concerned about how cooperative she will be with just the exam, let alone the poking.
She has came tearing into her roll as a two year old complete with at least one daily tantrum lasting 10 minutes or more over such things as itchy tights, not wearing her nightgown to church, too much milk on her cereal, finding the end of the spool of ribbon, and not being able to party in the living room at 4AM.
Perhaps I should go in myself, just for some parenting advice. You'd think by # 3 I'd have things figured out, but every child is so completely different from the others, I feel like I am starting over with each kid as they move from one developmental phase to the next.
On a good note, Andrew seems to be nearly completely recovered from his surgery. The first two days were hardest but now his only lingering symptom is that he is still really tired by the end of the  day. In a few weeks we will return to get things checked out and start back on his allergy medicine, hopefully with the good results.
So we are off to the doctor. Wish me luck, and pray for Becca's immune system!