Sharp pain on right side

I had an ultrasound today at my OB and everything looked good I'm 29 weeks 4 days. But about an hour later when I got home I started having serious, bringing me to my knees, can't stand up straight, makes me cry pain in my right side. My hubby freaked me out by saying the pain is kinda where my appendix is. I just thought at first it was ligament pain (I have a split uterus and baby is on my right side) but this is so sharp that I can't breathe or walk or straighten up. I feel like if it was something serious they would've seen it on the ultrasound? I dont know I don't want to be "dramatic" and call them or go to the ER and it be nothing. Has anyone experienced this ??