Curious what you lovely ladies think.

Yesterday I had some fairly painful aches in my lower abdomen on the right side. The day before I had one really sharp pain in the same spot then was fine the rest the time. Today I'm having a very painful ache about mid abdomen on the left side. I thought about going to the ER just to make sure everything was fine with baby last night (this has not been an easy pregnancy, started with threatened abortion at not even five weeks, followed by sub chorionic hemorrhage at maybe six or seven) before things felt fine again. This new ache on the left side has been constant for about an hour now. I don't think it's contractions. What do you ladies think? Should I go ahead and make a trip to the ER just to be safe, or not worry about it since the pain has no consistency?

Btw: I am 21w2d today, second baby.