The scales are not the only measure of progress. Have you had your lipids tested at all? Are you tracking your waist measurement? Are you achieving more with your exercise? Are you feeling better mentally?

I've also heard that when you're ill, the body can have this habit of retaining weight, in a sense so that it has more ingredients on hand to try and deal with whatever you're suffering from. I don't know if that applies to something as simple as a cold, but you can possibly find out by weighing yourself again once you're feeling better?