Is there something wrong with how much i weigh or is it just muscle?

Ok im 13 and i play ALOT of sports. Softball, basketball, volleyball, track, (SOFTBALL is the main, catcher and shortstop, for both school and travel softball) Im very small(skinny) but im 5'6( little taller for 13) and i run about a 6:10 mile.. 2years ago i wieghed 80lb, and i wanted to gain more weight by building muscle( for sports cause ive always played with MUCH older girls). Now im in 8th grade a weight 126 pounds but i still wear 00 jeans and xs everything else.(just like 6thgrade) Is it just the extreme amount of muscle ive gained, or is the something wrong. i dont look big but i feel big. Please reasure me if there is nothing wrong or tell me if there is