My scales are stuck

Could this be the dreaded plateau? My scales have been the same for 2 weeks. I lost 2.4kg over Christmas (surprising, but I wasn't going to question it), and then NOTHING. They've been within 0.5 of that for the whole 2 weeks. I've eaten pretty well and exercised 6 out of 7 days a week. I'm not sure where to go from here. The only thing I have changed is I have replaced one snack with a low carb protein shake. But I count it in my daily allowance. Will have a chat to my trainer today and see what he suggests. It is so disappointing when you work hard and don't see any results.