Sciatic pain while preg?

A
I'm 12w6 but since I woke up this morning my coccyx is killing me, I can't be seated anymore. It sucks as I will be hours tonight at restaurant for New Year's <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a>. Any suggestion? My doc is on vacation and I don't want to go back to ER (I was there yesterday for contractions), if possible