one day period?!

So in the exact day that eve predicted at cd40 I thought I had my period it was super light pink so I was like ok here we go.... later that night to the next day to today it's completely gone.... this was three days ago... is this normal? Could it be a chance I'm pregnant? Kinda hoping not because I'm going on a plane out of the country in 2 weeks... if there's a chance I am pregnant when would be a good time to buy and take a test?