Hi I'm 18 and today I went to the bathroom and noticed I have yellowish red discharge but I don't start my period for 5 more days and I never spot?

If it persists.... Having one day of a yellow discharge can be upsetting, but may not be anything bad. If however this persists more then 2-3 days, you start to notice an odor with the discharge, or any other signs of vaginal irritation or discomfort arise, then contact your gynecologist. There are several bacteria that may be causing this, but many times your body will take care of it on it's own.