Everyone says "Don't move!"


I'm just starting the bbt journey. I'm a teacher and my summer schedule is totally inconsistent. I figured the only consistent time for me is at 5AM when my husband kisses me goodbye as he leaves for work. I roll over, kiss him goodbye and say a few things. But everyone on here says to temp before you move. I don't get up. He leans down to kiss me. And honestly I have to roll over to get the thermometer anyway. So is it really so sensitive that i can't speak to my husband, give him a quick kiss before he leaves and THEN take my temp? Just curious how serious I need to be about this bbt thing.