BBT fluctuation?

Jessica
I have a really bad fluctuating temperature from December till today it almost seems like the only time it was almost steady was around jan 1st when I had AF and a cold.. My temp doesn't even follow the dotted grid on my BBT.. Any suggestions as to why this is happening is everything normal? An because my period was late in dec an I finally had it jan 1st now my period calendar says I get it again two weeks from the 1st of this month.. I'm worried.. Should I be?