What Causes Vaginal Bleeding After Taking Morning After Pill?

I am 34 yrs old. My periods hv always been fairly normal and regular. About 6 months ago I noticed I was discharging more than usual. It was enough to make me wear a panty liner. No odor no pain of any sort no itchy no redness ect.. The beginning of may the discharge stopped.. I had been on amoxicillin 850 mg for a bad tooth though so I figured maybe it took care of whatever was causing the discharge. I started my period on June 24th I usually bleed for 5-7 days.. On the 6th day I had unprotected sex and took the morning after pill.. My period stopped the 31st then 9 days later started again.. I know this could be a side effect of day after pill however I hv taken tht pill before a couple times and it had never caused me to start my period 9 days later.. I hv extreme anxiety and I'm horribly scared of doctors.. I'm always scared of them telling me I hv something fatal like cancer.. I hv been crying a lot over this lately cause tho I hv no other symptoms I'm freaking out. Please help me.