kayla - i have always wondered this. with my first bfp, i felt the sore breasts about 14/15dpiui - they even looked slightly different (veins more noticeable)
now i feel none of that, i am in the 2ww. I keep waiting to feel that to assure myself I may still be in this month, but from what i hear, some people never feel the same symptoms twice, so who knows!