My Periods Are Usually Very Painful And Heavy The First

My periods are usually very painful and heavy the first two days and I can tell when it is about to come,and I always make it to a bathroom before it happens. My periods are always irregular and have never been "on time". This month my period came out of nowhere, didn't get to the bathroom in time like I usually do, and there were no cramps, back pain, cravings, or irritability. My period has been very, very light and oddly colored. It comes in a light brown and a lighter red sometimes. Off and on. its almost like my whole period has been the ending of my period.