I found it really scary. It think it is horrible to have that every night. I used to do the same thing. However, I found that the only times I felt I needed to check, I was sleeping. So, being unsure about whether I am asleep is actually already a good indicator.
I think what happens with me is that I want to wake up and I can’t and then I panic and everything becomes scary. So, it is probably just that I want to wake up and I cannot.