In my session tonight I had 2 powerful involuntary contractions.

I have had a few good sessions where i really fell the nerves in my tailbone and anus light on fire. Tonight I really did not get much of that(believe i was too tired) but, at some point during my session my whole pelvic floor contracted very forcefully and pulled the Aneros in deep. It honestly scared me.
Is this normal? Should i learn to relax into it or is it something that i need to learn to suppress?