Vagina uncomfortable

So I don't know how to describe it well, but it's not the lightening feeling down there, but I get this pain when I'm walking. It feel like something inside is dropping and causes some uncomfortable pain. I am, as my dr puts it, up and back so I can't wear tampons without a very similar feeling happening. Does anyone else get this or had this around 33/34 weeks? Is it a normal thing? I don't feel it unless I am walking and only sometimes, like when im booking it ha! :)