Lately, (I'm 47) my menstrual cycle has been wild -- I go from three weeks apart, to six, then to four: What's happening?
It may be that you're experiencing the early stages of perimenopause. As we approach the age of 50, our hormones begin to fluctuate and estrogen levels begin to drop. But the fluctuations may not be consistent -- which is why you can have a normal period one month and an abnormal one the next.
The first thing to do is have a thorough gynecological exam. Your doctor may suggest that you have blood drawn during the first couple of days of your period to determine your hormone levels. Depending on the results of these, he may simply reassure you that all is well or he may suggest that you take birth control pills to regulate your cycle. But do have a checkup -- perimenopause is only one explanation. It could be some other disorder altogether.