What Causes Irregular Periods With Pain In Breast And Bloating?

for a few weeks now i have been feeling bloated and been have pains in my breasts but not all the time with the pain it comes and goes but the feeling bloated is mainly at night time. i was due on my period 11th this month but didnt come on. i do have irregular periods. today i took a test and it was negative then later on i started feeling very sick i nearly was but nothing came out. what could be wrong?