Any idea why my temps are lower every month?

Amy • Biz owner, was a teen mom to a now 18 year old 🩷. Baby #2 was a 5 week NICU warrior born @ 34 weeks in August 2020 💙. Baby #3 born at 33+2 in June 2023, currently in NICU 🩷

I’m 34, no *known* medical issues other than ulcerative colitis, which does not affect body temp. When I looked at my chart overlay for the past 3 months, it seems like my base temps have been getting lower every month. I have an appointment tomorrow morning with my PCP, I’m going to let him know I am TTC and ask that he do a whole bunch of preconception blood work for me, should have done it a few months ago but 🤷🏻‍♀️. Just curious if anyone might have some insight?

I have not changed diet, I have not changed exercise, I have not changed thermometers, I have not changed the time I take my temps, I have not changed the amount of time I leave the thermometer in my mouth after it beeps... literally nothing has changed over the past 5 months except that my basal temps are lower all the time.

This is our 4th month TTC. I got pregnant with my daughter 15 years ago while properly using the Depo shot *and* using pullout. She was an oops, now we want a baby and it’s not so easy. I know 4 months is not a long time but I’m just worried I may have a long road ahead