Why so dark

I had a miscarriage at 8 weeks back in August and a chemical pregnancy back in October. Today i took a test and is very obviously positive, i know i shouldn’t of tested so early but i was anxious and just couldn’t help it. My period is due Saturday (which recent months it has been coming a day early) which would make me around 8-9 DPOish, My big questions is why is the line SO dark, shouldn’t it only be a faint line since i’m so early and havent missed my period yet? Any input is so helpful thank you