Well it is hard to say what this is before suggesting a remedy because some woman do experience a kind of thick usually brown looking substance before or after there period this is completely normal, although you say it has a strange odour, Is the odour different from what your period odour smells like? because obviously the smell of your period isn't nice but you should know if the smell is abnormal or not...All i can say is if your worried visit your doctor...jenny

if the ordor is different than what your period smeels like you may wanna see a doctor. If it is the same it probably left over from last period that didn't get pushed out. I experience that for a day or so before i start my regular period.

okay yeah i would be worried too. i've heard thick brownish discharge before your period but not black. you should really go see a doctor just to be sure its not anything bad
best of luck

I've had something that almost sounds like this! Mine wasn't thick though. On the first couple of days of my period, I was getting black flakiness and it smelled a lot stronger than normal blood, but I figured it was just dried blood so I didn't pay it any mind. Then a few months later, I found out I was iron deficient (unrelated to period) and I've been taking iron pills. Ever since then, the blackness has stopped. Maybe you're low on iron too!