Fastin and phentermine

I have been on Fastin for 6 days now. Have not lost 1 lb. as yet. What it has done is stop my cravings for sweets, which is good. The thing I have noticed though is that twice now at night after eating something around 10pm on, I have thrown up. Very strange. Feel sick to my stomach, which is keeping me from eating.
Now, I've been on Phentermine in the past and lost weight. With Phentermine I also had dry mouth and lots of energy. I feel a little bit of a rush, but not much, and no dry mouth.
Has anyone had this experience of upset stomach?

Actually this is the only diet pilll that I have tried that I didn't really have side effects using. Its phentermine just like Adipex and Ionimin BUT Fastin is time released so I think thats why I personally didn't have that Blah feeling when it wore off and wasn't starving when it wore off.
Of course everyone is different in the way that medicines affect them...