This is my first cycle in TTC #3. I've been charting for 4 years to avoid and have felt completely confident in my abilities to know exactly when I O every month. My signs are always very obvious, temps totally predictable, even if my O day fluctuates month to month, I know exactly when it happens. But of course, this month, when I'm watching it so carefully and trying to conceive for once, things get weird! My coverline is always around 97.6-97.7. I typically O between days 13-15. On day 13 this month, I had tons of EWCM. We BD that day like crazy (as well as a few days before to be safe). Temp the next day was 97.87, and CM was much less and sticky, so I was sure I'd O'd. THEN, dpo 2 it was down to 97.54, which I didn't worry about too much, but thought it was odd to be so low. But then dpo 3 was down to 97.32. NEVER in 4 years has my temp dropped that low after ovulation. Then today, dpo 4, it was back up to 97.87. No I'm wondering if I actually O'd when I thought I did, or if it was really two days later and that first high temp was a fluke. BUT, based on mucus, I still think I O'd on day 13.
To simplify: (sorry I paper chart) Coverline 97.6
Day 13: EWCM 97.4
Day 14: Sticky CM 97.87
Day 15: Sticky CM 97.54
Day 16: Sticky CM 97.32
Day 17: Sticky CM 97.87
In researching, I came across fallback rise where temps can drop on dpo 2 or 3 and go back up. Could this be what happened? Crazy that this has never happened before. Pretty sure we should be good no matter which day I O'd since mucus was good, and we hit it a few days earlier as well, just want to pinpoint when I should expect AF and/or implantation dip/spotting.
Pretty sure it's too early for a triphasic shift. I had a triphasic ship after a one day implantation dip with my second pregnancy, but that was at 7-8 dpo and the shift was way higher than my post-O temps. This temp drop I'm talking about occurred at only 3 dpo and then went back up. Seems too soon for implantation already.
I'm experiencing the same thing on my chart this month, which is definitely a first for me. I looked online for "fallback rise" but most of the stuff I found was just message boards like this one. FF did say that it was a temporary temp dip 2dpo, but didn't elaborate more than that. From what I'm seeing, it seems to be perfectly normal.
Sorry I wasn't more help lol best of luck to you and fingers crossed that those temps stay up