BBT Dilemma!

I know that I have to take my bbt before rising out of bed everyday AND to take them at the same time. So here's where my dilemma begins. I don't have a fixed work schedule. I work rotating shifts i.e. day shift, evening shift and nights. So, I only take my BBTs before rising out of bed as much as I can which is kinda hard when I'm on call most of the times and getting called in at 3am for a delivery. So, should I still take my BBTs before getting out of bed? Or throw all of my data out and stick with CM checks and OPKs? Please advise