Certainly, it makes to talk to a doc, but it's not uncommon for you girls to have irregular bleeding prior to developing an ovulatory cycle. While they may be getting their periods, they may not be ovulating, and without ovulation, they are not producing progesterone. Without progesterone, their periods may come more frequent, with episodes of breakthrough bleeding.

Still, a pelvic exam is arguably warranted, regardless of how normal her bleeding might be.