brown discharge

I'm supposed to take my nuvaring out next monday.. the 30th i started to have brown spotting and everyday until yestwrday i was spotting more and more (always brown). Yesterday I put in a tampon, and when i took it out, it was brown and red, and well i started my period 4 days in advance.. I have an appointment schedule will my doctor, I was just wondering if it happened to anyone before and what would of caused this.. google is stressing me even more saying it couls be VPH or cancer etc.