What Does Appearance Of A Lump Under The Nipple Indicate?

HELLO, im worried that my girlfriend might be pregnant. We had sex 2 weeks ago,with a condom. 2 days ago she told me she had a lump under her left nipple and she felt soreness as well, all of a sudden it dissapeared today, she shows no signs of pregnancy at all. i had her take a pregnancy test and it turned out to be false, does the lump mean shes pregnant