Insecure? Very.

I'm 14 about to turn 15 in about a month & i'm super insecure. I'm a size 6 in jeans & a medium when it comes to tops. Is that normal? Bc i feel real fat. Plus, my bra size is 38B & 38C when using pushup but i could've sworn i was a 36C last year & was wearing a regular bra. Is this normal?