Sharp pains??

Brittany • Chloe Elizabeth 7-30-13. Sophia Grace 10-15-15. Baby #3 09-20-16
I'm 19 weeks exactly and am currently laying in bed on my left side with a pillow tucked in between my legs when I felt this sharp, stabbing pulsating feeling that lasted for about 30 seconds on the right side of my belly, a few inches below my rib. What is that? Round ligament pain possibly?