It feels like something is in the way when having sex?

For the past month, when I have sex and I get top, or do certain positions, it feels like there is something inside my vagina. Like on the side. It's very uncomfortable. It doesn't hurt me or him, but we can feel it during certain positions. It's never done this for the past 5 years I've been having sex so I'm not sure what it could be? Has anyone else ever experienced this? It's almost hard to explain what I mean by this, but I don't know how to stop it? Should I get a Papsmere? I'm really confused what to do or what it is.