That is very low. You're right to know low temps can sometimes be related to thyroid problems, but some people just have lower temperatures as well. I'm glad your thyroid is good.
Some women (myself included) have temps in the 96s and low 97s before ovulation and then they go to the mid-high 97s and sometimes 98s after ovulation.
I would think it might just be an odd temp. However, continue to monitor it and you may want to consider talking to a doctor if it continues to be that low.
You may know most/all of the following information but I want to make sure just for the sake of helping you!
1. Do you temp at the same time every day? It's the most reliable if you do.
2. Do you take it without getting up or doing anything before taking it? It's best if you don't do anything before taking it.
3. Do you breathe with your mouth open when you sleep? That could cause the lower temps. That's why some women temp vaginally.
4. Have you been using the same thermometer throughout the months?
5. Do all of your charts look the same?
I assume since you used two different thermometers that it was accurate, but it still makes me question the thermometers and the method.
I looked at your FF charts. Do you usually have a 23 day cycle? It's okay for it be 23 days, but usually you will ovulate much earlier in the cycle if that's the case. For example, one website says it will probably be around cd 7-13. You did have fertile cm around cd 8-11 and HSO cp in your June cycle. I notice the positive opk came later though. How long have you been using opks? I'm not so sure it would have given you the crosshairs for June if you didn't have the positive opk in the chart because the temps are still low/close to those prior to ovulation day. It would also mean you had a 5 day lp (luteal phase). It can cause difficulties if it is under 10 days. I'm wondering if it did occur earlier, but that your temps are not reading accurately for you.
My recommendations:
1. Don't panic! I know it sounds frightening but it will be okay!
2. Continue using the same thermometer for the rest of this cycle in the same way you have been doing it while paying attention to your temps and your lp.
3. If you have to, consider switching to a new thermometer or a new battery OR consider temping vaginally to see if your temps are the same next time (only if you have to have a next time).
4. Monitor your cm and watch for fertile cm in particular. Perhaps take opks around cd 7-13 or when you notice fertile cm to see if you do get a positive around then.
5. If on hypothetical next time your temps are still low or it appears there is not a higher shift in temps after ovulation or you still have a short lp, you might want to consider speaking with a doctor just to be safe.
6. Keep in touch. I really hope you get it all figured out. Good luck!
