Actually I think that you have made two good observations. The convective flareup appears to be to the south and southwest of the center, although pinpointing the center on IR imagery is always difficult. At 09/00Z I think that the center was around 23.0N 55.4W which would indicate more of a west northwest movement over the past three hours. Since the steering currents are quite weak, it could be just a temporary thing - or its also possible that the ridge to the north may have strengthen somewhat and the trough might have weakened somewhat. It will take a few more hours of observation. Also possible that the flareup itself nudged a slightly more westerly component to the track direction, but all the more reason why Bermuda needs to monitor Bertha's slow progress.
Cheers,
ED