Wound separation after tummy tuck?

I am 9 days post op and my incision has appeared to seperated, there is a brown discharge that is coming from the wound and there is a yellow mucus type substance in the wound. I am not sure what is wrong, what is the brown and yellow discharge? Is this normal or should I be worried? My surgeon has instructed me to leave it dressed for a week, how long will it take for these wounds to close up? If I walk will it split the wounds even more? Thank you!