How do I get my stomach flatter in a short amount of time?

I am 4ft 9in tall and I my weight fluctuates between 105lbs and 109lbs now when it used to fluctuate from 98lbs to 103lbs. I'm not fat, but I am starting to get a stomach pudge and it's really making me self conscious. What is the best and most effective way to burn this off fast? I am going on a trip on July 8th so what kind of workout can I do that will reduce my pudge? It's not that huge I just feel so heavy and I am starting to get people at work making comments about it but in a joking way. But it still hurts my feelings. Btw I am 24 years old. So any suggestions? Thanks