Is it normal for one breast to be larger, heavier, and lower than the other? i never really paid much attention before but i recently noticed one of my breasts in larger than the other? i think its always been like this, but i dont know?

It happens. Occasionally there is a dramatic difference in the size and shape of breasts. Symmetry/uniformity of size and shape are expected but there is usually a slight difference in the two for most. If you feel the status has changed over several months it is worth discussing /evaluating the difference by your doc.

A mild amount of asymmetry is normal. Left breast is larger and hangs lower in many women. One testicle often hangs lower than the other. It may be a cosmetic issue, but it not a health issue. Wish you good health.