I started using the NuvaRing on April 15th and before I used the IUD. I took out the NuvaRing on May 6th but did not have my period. So I put it back in 7 days later. On the 7th day I noticed around my nipples were sore and still to this day they are still sore. So is there a chance I could be pregnant or could his be due to the NuvaRing?