If you only get your period for 2 and a half days what is ushually 5-6 days long what could be wrong?

No not likely. Your body was probably reacting to some sort of change, however slight. Could have been stress, change in eating, sleep or lack of and sort of thing. If your overall health is good then a longer or shorter period isn't alarm for healthy pregnancy. Both of you should eat right, get good sleep, no stress, if that's possible, no smoking or drinking and have fun...