Basal Body Temperature (BBT) is the temperature immediately upon waking. Before I wiggle around, pee, make the coffee, or check my phone I rummage around under the pillow for my Basal Body Thermometer, listen for the beep, and slide it under my tongue.
BBT is a wonderfully addictive and informative way to track your cycles, but you need to have some sort of chart to add the data to in order to see the patterns. BBT's have very specific patterns each month, and it becomes easy and natural to find those patterns once charted out. There are different variations of "normal" but you will almost always have at least a biphasic chart (2 phases) meaning lower temperatures before ovulation and higher temperatures after ovulation. It's really fascinating actually. Here's an example of my chart from last month. I use FertilityFriend, which is helpful because it also lets you track symptoms, cervical mucous, position, and medications.
Ok, so you can see that my temperatures were generally lower during the first part of my cycle, then I got a big dip (this doesn't always happen, but is really helpful when it does) right before ovulation, followed by huge jump during/immediately after ovulation. THEN the temps stay high. The longer the temps stay high, the better. If they stay high past the day you would normally start your next cycle, then there's a very good chance you're pregnant. A big drop later in this phase usually means you will start your period the next day. In this chart, the program is putting together all of my information to estimating ovulation (it probably actually happened one day sooner though, after the drop). Once you have 2-3 months of charting, the program gets smarter, and more accustomed to your patterns therefore becoming more accurate the more you use it. There is also an overlay feature so that you can compare months/cycles on the same graph.
One thing about the temperatures, they don't lie. As much as I didn't want to see that temp drop in my chart yesterday, I knew in my heart we missed it this month, and my huge jump today confirmed it.
Here's to starting all over again. *clinks my giant cup of coffee* I'm going to go ahead with internal ultrasound on Monday to check on things in there post Clomid and make sure there aren't any problems. I'm guessing the Clomid is the culprit for these last two bizarre and short cycles, so I guess we'll try our hand at a natural cycle next month. (now where did I put that butter knife....)