I'm almost 24 weeks and I don't feel like mine have gotten any bigger at all. My boyfriend says they have but I don't see it one bit. If anything they look smaller to me cuz my stomach is getting bigger lol
I thought the same thing lol until when i was about 19w i was able to squeeze milk out lol. They don't look much bigger and have not been sore this entire time. I wouldn't worry too much about it you'll fill out and get milk more than likely (: