Blood collects on ledge in Mooncup - leeks out little holes - EEK!

I'm using a Mooncup for the first time this period. No matter how high or low I insert it in my vagina, blood collects on the ledge around the inside of the Mooncup just above where the little holes are, and then leaks out through them. I have to wear a pad to collect the droplets. I think I'm getting a seal - I do the sweeping-round check with my finger that the cup has unfolded properly, and I usually hear the sucking noise when it unfolds upon insertion. I squeeze with my vaginal muscles to make sure it's held tightly, too.

What am I doing wrong? I don't really understand how the blood doesn't come through those holes for everyone. I really want to go swimming with my Mooncup. Doesn't look likely. Please help!

daisy_samsie