What will i do?

Day

Hi, i just want to know if i'm pregnant or what... My breast is hurt but not too much just hurt for almost 2weeks. And my period is 6days late. By the i have an irregular period. My last period last for 9days. 5 days is heavy bleeding then the rest just slight or spotting. And sometimes i have an upset stomach i burf often and lower back pain. At 2nd day of having late period I try pregnancy test but its negative.