Confusing sex experience

When I was 15 I lost my virginity to my girlfriend at the time! I call her a hasbian (has been a lesbian)! She pretty much used me but that's beside the point! Every time we had sex my eyebrows and nose would get all vibraty like the vibration feeling u get when ur foot falls asleep! It wasn't uncomfortable... It was just weird! I still don't understand why it happened and it still does depending on the situation! Can anyone give me advice?? Or inform me on what the heck my body if doing!? Lol!