I usually take it anyway but make a mental note that it may be incorrect. Honestly, my temp jumps a degree over a couple days after I've ovulated.... I could take my temperature mid day and still confirm ovulation.. but that's because I know my temps pretty well by now. Looking at a chart as a whole usually confirms the outliers anyway... That said, I try to be extra careful when I know I'm O'ing! I tend to be more lazy the other days!!!
So... I might take it, but just not rely on it and try to be sure the next couple days you get to take it on time!