I have irregular periods ranging from 25 days to 32 days. I do use a menstrual cycle app to somewhat monitor my cycle. Based on the app, it has averaged my periods to be every 29 days at this time. My last period was on September 19. I had unprotected sex (no birth control or pull out method used either) the day before what the app predicts is my first fertile day. I began having swollen breasts, bloating, lower back and side pain next day so I thought it best to take Plan b pill, 36 hours after intercourse. About two days after I took the pill, I started feeling nauseous, dizzy, lightheaded, bloating, swollen breasts, feel the need to eat even though I am full, intermittent cramping and lower back pain, etc. and I wanted to know if I am likely experiencing side effects of the pill and/or pms, or could be pregnant.