Hmmm....well my breasts were not tender when I was pregnant with Kahlan, and I went from a DD to a DDD....and this time, they were sensitive for a little bit during the first trimester, but didn't get bigger until 2nd trimester when they were no longer sore...I'm now a 36/38 E and considering a reduction surgery (quite seriously, because it kills my back).
sorry, ramble, anyway yes your breasts can enlarge without hurting...