Round Ligament pain?

I've been feeling a dull ache in my lower abdomen, right side, almost my groin really, since yesterday evening. Hasn't went away. It's not painful, but definitely noticeable. I'm 19 weeks today. I know round ligament pain is normal in second trimester but I always thought that was more of a sharp, stabbing pain that only lasted a few minutes and went away with rest.  This has been constant. Almost like a pulled muscle feeling. I skipped work today and called doc but of course with it being Labor Day they aren't in. Is this normal?