Can't lose an ounce!

Options
I have recently turned 50 and have been VERY consistent with watchinbg what I eat and excercising. I race walk and do a boot camp class a number of times per week. I try to watch alcohol consumption and keep carbs at bay. I have been under 140 lbs for a couple of years and now I am 145 lbs and can't budge the scale. Help!