What Causes Vaginal Spotting With No Regular Menstrual Period?

hi i hope u can help me understand just alittle bit atleast what is goin on i had my period a couple weeks ago bout a week or so after i started to spot light pink and brown it has been three days now n it seems that the pink seems to b alittle watery and the brown more thick i have been gettin bad headaches and very little crampin off and on and it seems to b slowin down i have never had this before and it is nothing like a period also i started the nuvaring on the 1st n took it out the 6th or so cuz i did not like it at all had my period n now this my reg period usually starts the 3rd if that helps alittle to understand than i hope so