It is possible to get pregnant five days before you period if i'm irregular?

Yes and No: Irregular periods means one cannot predict exactly when her period will be, which means she cannot tell when she will ovulate. Looking forward, yes she can get pregnant 5 days before when she guesses her next period will come (because her period might not come until a week later). Looking backward, no she did not get pregnant 5 days before her period (because she just got her real period).