4 months PP and cramping

Asia • Mom of three 💙J Aug '08, 💜 E Aug '14, 💙 T Dec' 19. Wife 💍and eternal partner since Sept '10.

For the past month I've been having period like cramps on and off. My son only breastfeeds so I thought I'd get away with no period for longer. However I still haven't actually gotten my period. How normal is it to have this random cramping? Should I be calling my physician?