Chunky stuff!

sometimes I'll stick my finger in my vag and pull it out and this white chunky stuff comes out on it I'm 14 and I'm scared to ask my mom or someone is this fine should I be worried? is it a yi? Will this go away? It normally happens after I masterbate and then a lot of white liquid discharge will come out later in the day and for a couple of days does anyone else get this? Please help!