Progesterone level of 16 on a 32 day cycle

I’m a bit confused if you’re progesterone is checked on day 22 would that only be a accurate level for people with 28 day cycle I am usually a 31-32 day cycle and my level was checked at cycle day 22 with a level of 16 but I have no idea when I ovulated and if that’s really accurate since I’m not a 28 day cycle