How does anyone take a consistent BBT?

We are TTC and I question if I’m even ovulating. I’ve tried for 3 months to get this bbt charting down and I just can not do it right. I always seem to have something mess it up, whether it be I just HAVE to use the bathroom and absolutely can not hold it, my thermometer has moved from under my pillow (don’t have space for a nightstand) or my alarm jolts me awake and I sit up from being startled lol I just can’t seem to get this down. I’m mildly frustrated with myself. I’m trying to take it from the very beginning of my cycle but I have a heavy flow and can never make it through the night without having to get up and take care of it. 🤦🏼‍♀️ anybody have any tips. I’m lost.