Did i tear something on my knee?

Okay so i played softball for 1 year and when we ran i herd my knee pop it did hurt the second it pop but it stoped so i ignorded it so like 2 weeks later it started to hurt again and the back of my knee felt like really thight and it pops everytime i bend it and hurts ALOT its benn hurting for two weeks now . What should i do ? Ohh and my mom wont take me to the doctor idk why but she wont oh and my tHe back of my knee always feel tight it wont go away but the pain goes away sometimes and i have a limp when i walk