First of all, I'm sorry for your loss with the first pregnancy.
It's hard to tell for sure by sore breasts as to whether you are pregnant or not because sore breasts can also happen during PMS BUT....it is also a symptom that comes with pregnancy.
Of course, the only real way to know for sure is a pregnancy test and thankfully, there are those on the market now that can detect pregnancies before your next period is due by at least 5 days. Check to see which ones can detect that early.
In the meantime, since you have been trying and it is a possibility, treat it as though you are in terms of all of the healthy things you'd do if you knew you were pregnant....ie: not drinking or smoking, eating well, getting plenty of healthy rest and not taking any medications (over the counter or otherwise) that may harm a fetus.
Keeping you in my thoughts and hoping that the little stick that you pee on turns out a lovely positive for you and your hubby!
Please let us know!