what's that smell?

so my bf & I were getting it on the other day and he was fingering me (I was on the shot but it's up now, but I'm on like a mini period or something? lol)  and when he took his fingers out there wasn't really blood or anything on them from what I could tell maybe a little bit of a brownish color but not a lot. But he said it stinks really really bad and that it wasn't normal and I said idk what it is...and it made me really self conscious and he told me I should ask my doctor about it when I see her....but does anyone else have a similar experience or know what that's all about? I didn't actually smell it so I'm taking his word for it but yeah