You took a hpt and was neg but you are having light pink discharge and you are not supposed to have a period for another week?
Take another, they aren't always right. If that one is negative
it is possible for you to just have a messed up period or some
random discharge. Our bodies aren't always under perfect control.
It could be a slight break-through bleeding - your body TRYING to
bleed. Your hormone level drops dramatically causing your period to
come. Because it is still a week until this happens, your body is
not bleeding like a normal period. You should get your period as
normal in a week. If not, try another hpt.