About 5-7days before my expected period i started spotting light pink/brownish blood and has been going on for 11days now. bad? pregnant?

Depends: If you're concerned that you might be pregnant, take a home pregnancy test. It's normal for women to have occasional irregular cycle (i.e. Coming too early). There could have been a hormonal imbalance this month that caused period to come early. If you're having unprotected sex at 17 and don't want to be pregnant, use protection, ideally a condom and another form as back up, like pills.