It really seems like pregnancies can be so different from woman to woman, and pregnancy to pregnancy for the same woman.
Last time, my breasts were sore almost immediately; I went around squeezing them surreptitiously to reassure myself that I was pregnant
I was also very tired and peed a lot. This time my breasts themselves are not at all sore, but my nipples are killing me and latching on DS is getting almost to the grit-my-teeth-and-bear-it stage (more on the right than on the left, for some reason). I'm also very queasy, whereas I was not last time, but I am not at all tired (funny considering I never get a full night's sleep) and I don't think I'm peeing any more often.
And I definitely know women who barely had any symptoms at all. Heck, I know a woman who didn't find out she was pregnant until she was 14 weeks, because she never got her cycle back after her DS was born and caught the first egg without realizing it, and never felt pregnant!