I didn't. I didn't always take my temp at the same time and I didn't always sleep well before, sometimes I'd only get an hour or so of sleep before I woke up because I have insomnia, so I'm awake a lot during the night. It didn't affect my temps at all and FF had no trouble easily predicting ovulation for me. I got pregnant 2nd cycle. I think unless it's not predicting ovulation for you or everything is just really off, I wouldn't bother adjusting.