Spotting

ive got an appointment under GA on the 12th Mat to remove abnormal cells. inwas due my period around my first colposcopy but missed it it. I think think was due to stress. On Saturday morning I woke up with a little blood in my pants so assumed it was my period. However it is very light and only seems like bloody discharge? Sorry for tmi. I don't have cramps or anything. Do you think I should call the clinic to see if they can move my appointment forward? Very worried now as I have never really had any sporting before. I'm now concerned its developed into cancer as I've read that abnomral bleeding could be A sign. 

Thanks Emma 

I don't know if to leave it a few days to see if it does turn into my period?