C&C per req:
1. Composition isn't too bad on this one, but you have a large unfocused area image left. I would suggest moving the camera a little further right, and increasing the DoF somewhat so that the petals and stamen were all in focus; as it sits, the "bottom" of the bloom is very soft.
2. Again, this one would have been better looking more into the centre of the flower. The background, while soft, is still focused enough to be very distracting. In macro work, the rule of thirds often doesn't apply.
3. Very well done.
As noted by Ancient Sapper, your images are definitely under-exposed. I would guess by at least two stops. Exposure for this sort of work is tricky, always review your images as you shoot them, and go back and reshoot if there are issues. I think the contrast will be fine if the exposure is adjusted.
I would also suggest that more pleasant phrasing of your subject line wouldn't hurt either.
Just my $00.02 worth - your milage may vary.
~John