T.P.
I am a nurse and worked in Ob/Gyn for years. I would give your doc a call because, while this IS somewhat normal for a woman your age, she will want to make sure something else isn't going on that has a 'cure' like fibroids or a cyst. The average age for menopause (meaning 1 full year without a period) is 52, but women almost always notice that their periods go all crazy sometime in the mid-forties. If it is impeding your normal life, there is medicine that you can take to help regulate your cycles. Birth control pills or prometrium are often given in situations like your to add some predictability and normalcy to your cycles. The doctor may want to take a 'biopsy' of the uterine wall to see what hormones are in the blood to determine why this is happening. (is it menstrual blood only, is it a mid-cycle bleed, etc...) Good luck!
T.