Scary pain

So I woke up with the worse round ligament pain. Went to the bathroom and couldn't wipe (tmi sorry) because of the pain. Than I was sitting down eating and the pain turned into menstrual cramps. Very consistent. I laid down and drank water and the pain got much worse!!!!! It hurt sooo much to sit back up. I started to walk and slowly the cramps decreased. It was really scary. Should I have gone to the ER? Or could it have been one of those ligament pains? It's my second child so I know how contractions feel.