Only answer is to keep testing every couple of hours & have correction doses. But don't forget that the fasting acting insulin will keep working up to 4 or 5 hours, so don't overdo it. Up your basal insulin (lantus/levemir/whatever else) by 10% if that doesn't work, try 20% tomorrow, but watch out for hypos. You may need to up your insulin/carb ratio until your cold clears up too.
Good luck. Having diabetes is rubbish at the best of times when you're otherwise ill it's hell.