pregnant?

there's a chance I could be pregnant. glow say my next period is in 5 days. the clear blue tests I got say they detect pregnancy up to 6 days before a missed period. I don't feel any symptoms of pregnancy but my friends say I've been acting off for the past week. these were expensive so I'm only trying to use one in case something like this happens again... but I am a smoker but knowing there's a chance ive cut back a lot but I want to know asap so I can quit asap! should I take the test now or wait a couple more days?