Please help me....its about periods...ugh?

One day my stomach was hurting really bad and i felt hungry but just didn't want to eat anything.... so my mom asked me was i getting the weird slimy stuff in my underwear and i told her yes but then i said no but that was because i was just getting this weird wet stuff almost like i was squirting out pee or like i was peeing a little in my panies or you know like when you have to pee real bad and you cant hold so before you reach the bathroom some come out...yea like that.But know i think im getting what she was talking about ...its still the same peeing like thing i had before but now it has like this stuff in it like someone spit in my underwear or someone sneezed in my under wear its clear and i hate it.... before i wanted my period to come on so i can fit in with my friends now i just want it to go away...so my question is, was this what my mom was talking about and what is it..... and when i do get my period how to tell my mom or tell me how you told your mom. Thx i'm only 11 and need some answers because i really hate asking my mom questions like this because it turns all awkward and i feel like this is personal stuff so i shouldn't have to tell her. And how to go swimming or get in water with your period on.