Weird period

mrs.

My cycle started Tuesday night by Wednesday night there was nothing there. Im on the mini pill and have been since my son was a month old. The last period I had was when I first started my birth control thats been about 5 months ago. Tuesday was the first time I've bleed since then. It took all day to fill my pad and now its nothing.. has anyone else had a short return of a period or anything similar or should I contact my OB?