What school are you attending for your pre-reqs?
I went to Hunter for my pre-reqs and had a lot of trouble finding classes - they were either filled up or weren't offered at night (I work full-time days). Go figure! My solution was to shop around at other schools. If you're a CUNY student, you can go to any other CUNY (it's called going out on Permit). That's how I got all of my pre-reqs done (I went to Hunter, Lehman, BMCC, and Medgar Evers). It wasn't the most fun thing to do but I'm now finished and couldn't be happier. Go to the www.cuny.edu
and check out every school in your borough (or NYC if you're willing to travel a bit).
The one hitch is that you can't go out on Permit more than 2 consecutive semesters in a row. But, you can always attend a CUNY school as a non-degree student - I think the tuition is a little higher but not much.
If you do decide to do this, I would recommend taking A&P I, II at the same school - different schools cover the chapters in different semesters and you could easily miss some pretty important systems.
If you have any other questions, feel free to ask! Good luck.