3months postpartum not breast feeding. no period yet. cramping on and off for a month but no period. reason to be concerned?

Irergular periods : Irregular periods are one of the most common problems obgyns treat. If this is one time problem it usually resolves on its own. If this is a recurring problem you should be evaluated. There are many options available to help regulate the menstrual cycle. If you are trying to conceive the schedule a visit. Schedule a visit to see if you are ovulating.