Hi there.
I'm no medical expert, but you need to get this checked out as a matter of urgency. Sometimes (and I stress sometimes) it can be a sign of an eroded cervix, or it could be a multitude of other things, most of which are easily treatable.
If you have a Mirena or other coil, sometimes if the strings are a little long, they can cause minute scratching on the inside of your vagina, which after all, is a very sensitive place.
Let us know how you get on, hun.
TC
Ruby xx