Is it normal for your breasts to be bigger than expected after a breast augmentation?

Hello. I was originally an A cup and I got 400 and 375 cc under muscle high profile mentor gel implants two months ago. I was told I was going to end up a DD cup at the most! I’ve just been measured at a G cup which is so much bigger than what I was told I was going to be! I’m not sure if this is normal and a sign of something wrong is if it’s just that implants sit differently on each person. I’m 100% happy with my boobs I wanted them as big as possible but am just curious. Thanks.