hello, My last period was on aug 19 lasted for 5 days on a 28 day scale. i had unprotected sex on the 31(1st day of fertile window) the 3rd and 5th( ovulation ). i took a 2 dose next choice pill,one on 7th one on 8th.im having lower abdominal pain , dizziness ,lower back pain , mild headaches, and tiredness. cani be pregnant?