Round ligament pain?!

Period is a week late, I'm testing on Thursday morning. This evening I was laying on our couch and sat up really fast. I had a very sharp pain in my left side and the best way I know how to explain it, is that it felt like my "uterus twisted". It scared me so I did some research and came across round ligament pain. Would it be too early in a pregnancy for me to experience this? AF was due on 7/8. If I am pregnant I would be about 5 weeks.