Pregnancy is possible, but if you had spotting around Sept. 1 for a couple days, that probably would have been implantation, not this spotting that's gone on since the 26th, so it would be more than soon enough to have a positive test. It's quite possible it's hormonal changes causing the sore breasts and that or stress causing the delay. If it feels like you're going to start your period to you, it most likely will start soon. If it doesn't, try another test in a few days.