I had my Mirena removed on 11/21/12 and I started the nuvaring . I started my period on 11/18/12 and removed ring on 12/12/12. i recv dark brown blood on sat 12/15/12 and then it went away. i put my new nuvaring in on 12/19/ 12. ive had unprotected sex and im not sure if its safe to have nuvaring in since i did not bleed is their a possibility that im pregnant or is my clycle changing from removing the IUd to inserting the nuvaring