What do the experts think, should my breast get smaller if i lose weight?

Maybe: Breasts consist of skin, fibrous tissue, glands, and fatty tissue. Anything that diminishes your body fat including weight loss would decrease the fatty portion of your breast tissue and, therefor, decrease your breast size.

Possibly: When you lose weight you do not have control over what parts of your body lose over others. A healthy and diet exercise program will cause weight loss throughout your body. If your breasts shrink too much, talk to a plastic surgeon about your options for breast enhancement.