Cold Uterus?

I’m 44 TTC #3 with my fiancé who is also 44 and in good health. Has anyone had an issue with a cold uterus? My bbt temps are low to begin with, 97.18 on day 2CD. I believe I have poor blood circulation because I’m always cold. Two months in a row, we have been able to get the egg fertilized because I start to feel the pregnancy symptoms after 3dpo, about bbt 98.45, without ever getting a BFP. But, I know my body and these are not usual OVU symptoms. On 11dpo, the symptoms completely disappear after a day of weird cramping and headaches and then my temp drops, 97.89. I do have PMDD and that starts right up about 13-14dpo like clockwork and my temp drops even more 97.30. Has anyone else experienced this? What did you do to get your uterus to warm up and help with blood circulation? I do have a doctor appt on 3/11/19.