I am confused


I have brown goop in my panties. Normally I have clear goop why do I have this my last period was on the 11th to the 17th of October and all my <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period apps</a> say I ovulated on the 26th of October and I’m only 17 years old why is this happening to me should I go to the doctor? I’m nervous.