it is normal for your period to change because your diet has changed drastically. I wouldn't worry but if you are sexually active I would do a pregnancy test just to be on the safe side
it was the exact opposite with me- i had periods that lasted 3 weeks, then 2 weeks break and another 3 weeks period now THAT was uncomfortable
from what i've read and heard, CD does seem to mess up the periods, but it will all sort itself out after a while.