Hi,
Welcome to the ehealthforum and I am glad to help you out. Soreness of breasts and nausea can be the early signs of pregnancy but it can be caused by other causes also like hormonal imbalance, pelvic infections etc. Moreover since you had your periods, chances of pregnancy are less and this bleeding can be due to irregular periods. For confirming the status of pregnancy by urine for pregnancy test (UPT),the most accurate way to test for pregnancy is to wait until after your period is due.
First appearance of pregnancy hormone, HCG, due to implantation occurs 6-12 days after ovulation. Ideally the urine for pregnancy test should be done 1 week after missing your periods. But you can test at 9 or 10 days past ovulation with a sensitive ( 20 - 25 mIU ) pregnancy test.
I sincerely suggest you to do a urine for pregnancy test or get serum HCG levels estimated. For that please consult a gynecologist.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care.