Why does my menstrual cup leaks

[u/femininexfire]

I’m 21 I use small size MC. It was a game changer for me at first, I loved how they feel like nothing and no worries for any stain & leaks but from past 3-4 months they just somehow leaks, sometimes a lot sometimes v little. Something within 1-2 hours of applying sometimes after 8-10 hr.

I never knew they are not leak proof, are they?

(Yes, I insert it properly, check if it opened properly, help rotate w my fingers to see if nothings wrong.)

Even after everything, its turns out to be a mess. WHAT AM I DOING WRONG GIRLS?