im 18 years old and have been on the nuvaring for 5 months now. i have currently been on my period for 6 weeks now with a steady flow but last week i started to bleed heavier and i started getting cramps(ive never gotten cramps before) along with a sharp pain in my lower back. the last few days a lot of tissue like stuff along with dark red blood have also been coming out. i have unprotected sex from time to time but i went to planned parenthood last week and they told me im not pregnant. can anyone help me or know what is happening?