is this sleep paralysis?

last night i went to sleep laying on my back ( i usually don't ever sleep on my back) and had a nightmare. i felt myself wake up from it but i couldn't move or open my eyes and my heart started beating so fast and so loud i felt like i was about to have a heart attack or a stroke so i just layed there for a minute until my heart rate slowed back down and i could open my eyes again. that's not all. i went to the bathroom came back and went back to sleep (on my back again) and had another nightmare which caused me to dig my nails into my thigh (i guess from trying to fight off the monster in my dream or just from fear ) right after i did that i woke up unable to move again my heart beat going crazy and unable to open my eyes. when i finally was able to move again i went to the bathroom to look at the damage i had done to my thigh, it wasn't bad but i was still really scared. i sincerely thought both times that i was about to have a stroke with the way my heart was acting up but i told my sister about it this morning and she said that it sounded like sleep paralysis. is this sleep paralysis or should i seek medical attention? also im almost five months pregnant if that helps with your answer. could this harm my baby as well?