Powell130- Non-BBT thermometers aren't super accurate, so being .2 or .3 off is normal for a non-BBT thermometer. That's why using a BBT thermometer is so important. Also, as estrogen increases in your system before O, you may notice your temp getting lower and lower. And, as always, your resting temp will always vary depending on the time of day due to hormone fluctuations. I'm not sure I answered you question very well, so let me know if you have more questions.
overanalyzer- After a +OPK is can take 2 days to O and then another day to see an increase in temp, so lets see what your temp does tomorrow. Also, forgive me if I'm getting this confused, but I'm pretty sure normally you were doing your OPKs in the AM, but on the day your got your +OPK you had tested mid-day. A surge can last a couple days, but you could have missed the beginning of it with doing your OPK at the wrong time. If you happen to be one of those women who ovulate really quickly after you begin to surge, it is also possible you O'd on the 21st. While I can't pinpoint anything at this point, I'd say give it a couple days to see what your temp does. And in the mean time, keep BD'ing. If your surge didn't cause you to O, you will likely re-surge again soon. You want to make sure you keep BD'ing until you have a noticeable and lasting rise.