CD20, 5?dpo

My chart this month looks weird to me. Looking back at my last 2 charts, I haven't had temps anywhere close to the coverline post-ovulation (until the day before AF arrived), but this month my temps have been back there a couple of times already. And my post-ovulation temps are normally quite a bit higher than my post-o temps have been this month. Have any of the rest of you experienced this? Does it mean anything, or is it just one of those things? Our bedroom temp has been the same (we have a digital thermostat), and I've been wearing more clothes the past few days than before, so, if anything, I would have expected the opposite pattern from what I'm seeing. Monday and Tuesday were mornings in other people's houses over the holidays, but I didn't notice the bedrooms being especially warm or cool. I would have thought based on CM that I o'd on Saturday (CD14), which is what Fertility Friend says if I tell it to discard Tuesday's low temp, but that feels like cheating.

I am also wondering if it is perhaps time to replace my thermometer. This is where I fess up to having used a regular digital thermometer rather than a BBT since I started charting. Since my charts had looked pretty much as expected, I didn't give a lot of thought to it. Now that they seem odd to me, I'm wondering if I should go get a BBT. Also, today, my temp was more than half a degree higher after I got out of bed and walked ten feet to the bathroom (I don't normally check twice; I was trying to test the thermometer), which seems like a big shift without much movement. Anyone have any thoughts on this?

Finally, in case I decide to make the purchase, can anyone recommend a good BBT (and tell me where to buy it, if you know -- our local pharmacy doesn't carry them)? The features I'm looking for are: (1) backlit, at least when turned on, as it is dark still when I temp; (2) doesn't beep constantly -- ideally, beeps once to let me know it's on and beeps a second time when done (my current one beeps every few seconds to let me know it's working, which drives me (and P) nuts); (3) saves the most recent temp, in case I fall back asleep before checking the reading and need to use the recall function to learn what it was. My current regular thermometer does 1 and 3, but not 2. It is sensitive to a tenth of a degree, and it seems that people's BBTs are sensitive to the hundredth, though I'm not sure I really care about that. Much thanks in advance for any advice.