breastfeeding only wants right boob

Destiny
So I have been trying to breastfeed my 16 day old. We are getting better at it but she doesn't want to latch on to my left breast. She will throw a fit if I try to put her on it. It's smaller than my right breast but it was like that before I even got pregnant. It has plenty of milk in it. She just refuses to take it most of the time. Any reason why she does this?