TMI picture...I need HELP!

I went to the doctor a week ago to get my IUD checked. Everything was great. Around the times of my period I bleed a bit after having sex with my husband. She said that it was normal, but gave me some capsules/medicine to put in my vagina to ease the bleeding and treat some irritated areas. She said everything was normal. I put in the medicine as directed, each night for 6 nights and NO sex. I'm not sure if this is important, but the medicine isn't antibiotics or anything. She just said it would help. 

My husband and I had sex the night after my last capsule. Then today, THIS came out of me! I haven't worn a tampon for the last month and the only thing I have put inside my vagina since the doctor looked inside me was the medicine she gave me and my husbands penis (no condom). I haven't been in pain, I just think it's weird. 

Does anyone know what this could be?? It has the consistency of paper, but I don't put paper in my vagina! Is it my IUD???