Implantation with no bleeding

So last night I was sitting on the couch and I felt a very sharp sudden pain that lasted for a few seconds on my left side . That was followed with stomach tightening and now my areolas are getting darker and my nipples are really sensitive to touch. I don't have a doubt in my mind that that was implantation but my only thing was I didn't have any spotting does that come later or is it possible that it won't come at all ? I was 9 days post <a href="">IUI</a> and 11 days post ovidrel .