Does HCG Diet Cause Vomiting?

i have been on the hcg diet. I took my hcg drops as followed. waited 25 before I eat my meal. felt stuffed after 10 bites. I put down the fork, than all of a sudden I felt sick. I went to the bath and threw up about 4 times. is that a side effect og the hcg diet? I have never had this happen before. I have only been on the diet for a week.