I have been overweight most of my life. my period has come and i am beginning to lose weight but my brest are still not "full". i've lost some weight.

Still developing: Congratulations on achieving a healthier body weight. Losing excess fat has long term benefits. Breasts come in a wide variety of shapes and sizes. Most of what you've seen in magazines is pushed up, air brushed, or even surgically enhanced. There's no need to compare the size or shape of your breasts to anyone else. With weight loss, the skin may be loose and can regain some elasticity over time.

Breast development : Thelarche(breast development) occurs over a spectrum of ages but usually in later stage development by upper teens. That you recently got your period shows that you likely have normal hormones. There is natural genetic variation and it maybe that females in your family may have late breast development or smaller breasts. However, you should allow your body to continue mature on its own schedule.