Breast size has nothing to do with milk production. I was a small B cup with my first pregnancy and didn't have any increase in size. I started leaking a lot at 14 weeks and thought I'd have my milk right away with how much I leaked, but my milk didn't come in for 5 or 5 days after I gave birth. I was a full C cup while nursing my daughter for 16 months. After I weaned her I went back to my normal B cup. My mother constantly told me I needed to give my baby formula because small boobs won't produce enough. I had an over abundance and was able to store milk. Your body will meet the demands of your baby. I'm now almost 12 weeks with my second baby and I've had a lot of breastfeeding growth. I was almost an A cup, due to weight loss, and I'm now a C cup and I haven't gained any weight. It's crazy how different your body is with each pregnancy. I can't imagine how big they will be when they have milk again!
^^^ PP is right. I'm tiny, 34b. Milk didn't come in til after baby got here and I produced enough for her. It's not the size that matters. I didn't start leaking with my first til my milk actually came in. It's totally diff. With my second though.
Not everyone leaks and not everyones boobs grow. I wouldnt read too much into it yet. Your milk wont come in until after baby is here.