Ay, alam ko yan kasi nangyari din sa amin, after period, may brown spotting pa for a few days, usually old blood lang talaga na delayed ma-flush out, so normal siya most of the time, especially if walang cramps or weird smell! But since nag-last na siya ng 6 days, I'd suggest checking with your OB lang to be safe, just para ma-rule out any hormonal changes or infection, kasi better safe than sorry lagi with these things, no? Kasama mo lang sa worry, girl!