like hollie said, it's not like we can examine you right now. but from what you describe, it sounds like your lining was a little scraped up when he put his fingers in you. this is pretty common and can be avoided if he uses rubber gloves and lube next time around.
thing is, your vagina is lined with tissue similar to the stuff in your cheeks. it scrapes easily, but it also heals up easily. and the stuff in your knickers is just a little bit of blood. it's brown because it's a little clotted and dried (dried as much as you can get in a damp place like you vagina).
there is a possibility i am **WRONG**. if this brown discharge continues for more than a day, then I am probably *WRONG* and you need to check with a doc.
but if i'm right, then you go to your local drugstore, Target, WalMart, Kmart whatever and buy a box of rubber gloves and some lube. Even KY Jelly would suffice. Better that than any scary splotches in your drawers.
A waist is a terrible thing to mind.