Help! Skin like chunks coming out of my vag after sex!?

Please!!! I need some sort of insight I'm scared to ask anyone I know and I don't want to worry my boyfriend. Earlier right after having sex I wiped myself and a fairly large skin-like chunk was on the cloth. It looked greyish I thought it was just something that was already on the cloth until I saw more tiny chunks like things on the bed, my mans balls, and a little more around my vag. I have no bad smell or itching. My period is due in 6 days and I'm not sure if it's related to this, I'm 23 and have never had this happened, also I've been with my S/O for 3 years. Can someone please give me any insight or advice has anyone ever had his before?