Why is my period so short. age 37. perimenopause?

Time 2 get a checkup: There are a lot of reasons for short periods and it's worth getting it checked out. It could be reflective of thyroid disorders, non-hormonal gynecologic problems such as fibroids, and others. Your OB/GYN should be able to help you sort it out. Pro-tip: when you go, describe exactly how is it short - the number of days of the flow, or the number of days between periods?