Nope. Most ladies have slight contrasts in the shapes and sizes of their bosoms (one areola focuses north while alternate focuses south, for instance). It's ordinary to have one breast bigger than alternate; now and again, even by a glass size or two.
As long as this size distinction isn't new, you're OK. Be that as it may if one breast has abruptly been able greater or feels diverse (thicker, more full, or knotty), you have to be looked at by your doc. An one-sided (uneven) change could be an indication of a pimple or even a tumor.