Reality check into Sleep Paralysis

The title explains it. Mostly everytime i do a reality check in my dream, while in bed, i go in and out of sleep paralysis. Am i not waiting as long as i should for the dream to become more stable? I'll just be laying there in bed and do my scheduled reality check and bam, sleep paralysis. After the sleep paralysis is over i either wake up or forget to do another reality check. This has happened two times in four nights.

Any ideas?

I would like to note that this is after a WBTB so lucid dreaming is fresh on the mind. Plus, i've gotten into a routine of doing reality checks in bed because that's when i realize i am dreaming.