Same temp 3 days in a row?

Why is my temp the same 3 days in a row and then very close to the same on the 4th day? Seems strange idk what that means! I checked the thermometer by taking it at a different time in the day and it was a different temperature. I thought maybe it could be the thermometer.

This is my first month doing bbt. The only other time I ever did bbt was the month I got pregnant with my daughter 2 years ago.

Just kinda annoyed that I can never have a nice straightforward chart. Everything with me is just not typical. Ugh.