I just got called myself for March 25. I'm working on getting a postponement since I'm due to give birth on March 21. I don't get excused, just postponed for a few months. But I need a doctor's sign off for that.

Self employed, in CA, is not an excuse. Must be, as the OP above said, extreme hardship. We have a 1 day / 1 trial system here. Generally you go for one day and if you aren't picked for a trial your service is done. It's pretty easy to be 100% honest during voir dire and not get picked.