Is bra size 30B convenient for my body?

okay guys so I'm 13 my bra size is a 30B, my weight is 54 kg or 50.4 sth like that I dont really remember (but im not fat)im confused :S and my height is 162 cm so is my bra size good or small for my body?? And I got my bra size from the internet website for calculating bra sizes and stuff so I calculated mine and it was 30B so I dunno if u guys can send me a link that has pics for those bra sizes so I can see that it's really my size or not I would be really thankfull and pls for my weight in relation to my height am I underweight or Normal?? And is it good or bad?? Thank u so much again :)

im a 30B aswell. and I'm also 13. except I'm slightly shorter than u. I'm 159 and my weight is 38 kg. your breast size doesn't matter, I'm obviously shorter and smaller than you but I still have the same size. There isn't a good or bad. YOu are perfectly normal (: TRUST MEEE.