Is this concerning?

So far my BBT Keeps dropping and hasn’t risen again yet what does this mean? Is this a bad sign? Does this make me out already since it’s almost below the cover line? I’m only 3 DPO.

** I just switched from morning shift (7am-3pm) to night shift (3pm-11pm) I take my temp at 4am every morning could shift change be effecting my BBT?