Diet pills & birth control? HELP!

Im struggling with my weight a lot and I don't have a whole lot of time for exercise. I've tried dieting alone and nothing happens. And it's so hard because I feel hungry all the time! I really just want to feel moderately comfortable in a bikini. I was wanting to try a dieting pill but I'm scared it might affect my birth control. I've been on the pill for about four years and I have sex regularly with my boyfriend whom I live with. Although we love each other very much, we are NOT ready for a child at this point in our lives. My mom was on a dieting tea when she got pregnant with me (on accident) it was washing out her pill. Any tips or certain kinds of dieting pills I could try without affecting my bc???