Late period + discharge

Hey <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> ladies! I'm only 17 and have had super irregular periods ever since I started my cycle 3 years ago. I'm sexually active and have sex with a very committed SO *frequently* I haven't had my period since the beginning of January and for the past week and a half have had bloody, brown discharge that varies in amount and color. Sometimes it gets worse after sex. Any info would be appreciated!