Worried

I'm a 24 year old college student. For as long as I can remember, my periods have been irregular. Sometimes I would have them for a few months and everything would be fine. Other times, like now, I'd miss those periods. Today is actually day 56 since my last period. Recently, in the last week I have experienced brownish vaginal discharge, but no period. At first I did, or thought I did, some of the signs that I was getting my period but that never came. I do masterbate with a toy, so that's how I saw the brown stuff. When I do get my periods, they are the normal 5 days and my flow is the same. No complications or anything. I'd like to know some opinions or if anyone has experienced something like this. I'm not sure if I should start freaking out or not.