My cup smells loud

Hi,
I hope I am posting to the correct area. My question/problem is this. I have a Meluna cup and a Keeper cup. I notice that my Meluna cup even after washing and boiling it has a loud smell of blood. I can smell it when I open my purse and my cup is stored in the bag it came with. Does anyone else have this problem? My Keeper cup doesn't really smell at all but the Meluna does and it stained really bad?? The staining i don't care about but I would like to learn how others get the smell out. Any suggestions would be helpful.
Oh does anyone notice that wearing cups gives them gas? I know that since wearing my cups it seems to put pressure on my rectum causing me to have gas?