Haven' t had a period in four months this is the second time this has happened but ob says its not menoupause. what else could it be?

Perimenopause?: Menopause is defined as cessation of periods for a year. Prior to that, during the perimenopause, periods become more irregular and less frequent for many women. This is also a time when pregnancy can occur. An obgyn can sort out the causes.

Likely perimenopause: In the year or two before menopause, it is not unusual to have more irregular periods, even skipping them for several months at a time. Officially you are not in menopause until you go 12 months without a period. Blood testing might indicate impending menopause, but is not the final answer. Ask your doc for more of an explanation as to what he or she found.