hCG drops made me sick!

I have no idea what had happened to me. I mean, I know that hCG drops made me sick but I don’t understand why, because none of my friends had anything from taking these drops. I am the only one who has problems. The worst thing is that the doctor can’t give me any explanation regarding what happened to me. He has to do some more test in order to find out. I really hope that it is just an allergy.