not a problem, everyone is different. When i was pregnant with my first daughter I never got sore breasts.
It varies with every pregnancy. With my first son I had sore breasts at 6 weeks and with my pregnancy now I didn't get sore breasts until 8 weeks and now they are still pretty sensitive.
Consider yourself lucky if they don't get sore!
Every pregnancy varies. With my dtr, i couldn't wear a shirt let alone put a bra on. Very uncomfortable all day long due to the sensitivity and soreness. It was also difficult to sleep. With this pregnancy, I have had no breast soreness however, my nipples are very sensitive. I will take the sensitivity over the soreness anyday.