Abnormally light period after miscarriage?

Aislin
It's been about 5 weeks since I miscarried, and I was told to expect my period about 4-6 weeks after. I was told nothing else but google basically told me to expect the period from hell. 
A few days ago I was convinced I had fallen pregnant again but all the tests said no and then I started spotting - I normally spot a day or two before my period and then all hell breaks loose with very heavy very painful bleeding. 
But I've been spotting for 5 days now (TMI), very light only there when I wipe, brown blood and no cramping. 
Is this my period? An implantation bleed wouldn't last this long surely, and I'm still testing negative so I'm fairly certain I'm not pregnant. All the tissue from my miscarriage passed so I don't think it's that... 
Anybody else had this? What the heck is going on?