Is my cup too small?

[sammi_j1234]

I am a young virgin and this is my first cup, I have a size one lunette clear and I was just wondering if it is too small considering that I find it very easy to remove and break the seal. I horse ride and had a riding lesson on my first cycle using the cup and had no leaks. The only thing that prompts me to wonder whether my cup is too small is when swimming water always ends up filling the cup up. I have only used my cup for one cycle so far but have been swimming with it in multiple times not on my period, always the same result cup filled with water.

Thanks so much,

Sammi xx
EDIT: Thanks so much it doesn't leak at all in other situations to I think its the right cup for me. I may be one of those lucky girls that gets water in their cup during swimming. And thanks again guys.