Help!!!!! SOS

So last week I started having mild cramping with lower backache I thought nothing of it as its the week af is due I have pcos so sometimes my cycle comes a few days early. Well I cramped all week nothing then Friday I had thick brown spotting I put a pad on thinking af was going to start but I only spotted not enough to fill the pad. The next day the same thing happened and Sunday I put on a tampon because the flow picked up just a little, by Sunday night it went back to spotting nothing Monday and spotting Tuesday I'm normally a gravy flow from day one to four with five spotting. Today I've had mild cramping and my lower back is hurting and TMI but discharge is clear thin and sticky anyone been through what I'm going through.