Hi!!
Yep, EWCM can absolutely start 5 days before the actual O day. For me it does! It does start pretty slowly though, the first days aren't as stretchy as the days right before the egg drops.
With regards to the pics, that's definitely some very fertile CM right there! By what you said it's absolutely possible you O'd on CD12, but do you know if you still had the same stretchy stuff on CD12 or did it already dry up by then? Because like I said, most of the time, the last day you see EWCM, is usually the day you ovulated.
I dont use OPK's but based on research I've done, a lot of the time, by the time an OPK is positive it can be too late for the sperm to fertilize the egg in time (they can take up to 10-12 hours to reach the fallopian tubes). An egg should be fertilized as SOON as it drops; its viability decreases very fast, so even if a sperm does make it all the way up there, but only toward the end of the egg's viability timeframe, implantation likely won't take place.
That's why it's so crucial to BD 1-2 days before ovulation.
As for BBT charting, the principle is actually quite simple: your temps during the 1st phase of your cycle, before O, will be on the lower side, and as soon as you have ovulated, your temps will rise and stay high until your next period.
You'll have definite confirmation that you ovulated after three temps that were significantly higher than the previous 6.
Sounds complicated right now, but I swear it's helped me so much and gave me so much insight about my cycles. Once you have completed a full month of charting, you'll have a very good picture of your cycle and the health of your cycle.
Take a look
here to see my charts.
The crosshair marks my day of ovulation, E is for egg-white, and "I" is when we BD.
