Round Ligament Pain?

Nicole • Wife! Mom to a beautiful baby boy, expecting baby boy #2 in June 2017!
Can someone describe this pain to me? I've had pains on my left side since Saturday. It's dull for the most part and occasionally severe. The pain in located on my left straight out from my belly button a few inches above the hip bone. I'm 13w+1 (first pregnancy) so not sure what I'm feeling and if it's normal.