I don't think the space in front of the flower really adds anything to this pic.
You've done a good job using a large enough aperture to give a nice blur to the background, but not so shallow that the petals are blurred as the flow away from the center.
With B&W flower shots, it is difficult to get a really Grade A one. Since there are no pretty colors to draw the eye, you really need to focus on dramatic lighting and texture. Keep at it.