pain in myyyyyy butt

Lovemylife • Mom to two awesome girls. 1 MC. Had my rainbow baby boy 6/5/2017!!!! So in love 😍
This is my 4th pregnancy but 3rd baby. I'm 28 weeks and a day. I was driving and got this bad pain in my butthole (sry tmi). It wasn't constant. It would come and go but was sharp and short lived. No idea what this is. Anyone know? Normal? Never had I with any other pregnancies but I am carrying this one super low. Can a baby kick you in the butthole? Confused.