It's weird that you say that all the pain is in the left hand side of your body. This is something I've been having for 3 years now, sometimes really bad, sometimes it eases off totally. Once I was pregnant I started to worry about it a lot (and before that I took random pregnancy tests even though we weren't ttc, just because I worried about ectopics). They never could come up with any causes. Which is unnerving, but I learned to live with it
It's a difficult call, but I think I'd wait just a little bit longer unless more bleeding or anything occurs.
Fingers crossed for you, whatever you decide to do.