I had protected sex with my gf on 8 th day of her cycle and from 10th day her left breast got enlarged which is enlarged till now, there is no pain , nothing else is happening. Just one enlarged breast. She is expecting her periods after 4-5 days. What could be the reason for this problem? Is it an early pregnancy symptom? Can someone can have pregnancy symptom just 1-2 days after sex? (Her menses are regular and of 26-28 days).