Brown Spotting a week before my period

hi, im not really used to this stuff but here goes.
I'm 17 years old i just started being sexually active with my boyfriend about 3 months ago. My period is due on the 22nd of this month. but i started getting brown spotting which almost looks like my period. But its brown. It started on the 15th and has been happening everyday since then. I was just at the gynecologist on the 13th, she said i looked healthy but i there was no discharge then. I'm kind of scared cause im not ready to be pregnant. I just graduated. So if you could help me out I'd be grateful.

I got my first period this year in April, i am 15. It is now almost July and i still have not gotten it yet. RIght now though, i have been getting what looks like my period, but it is totally brown. I have gotten it beofre, but never for this long, i have been getting it for about a week, off and on. What is it??! What should i do?!