Hi jedigirl
The general principle is that as others have said FSH levels rise as oestrogen levels fall, to try to stimulate the ovaries, and falls as oestrogen levels rise - so that HRT should reduce FSH to some extent. However the oestrogen in HRT normally gives systemic oestrogen levels nowhere near those experienced at the pre-ovulatory peak so nothing is working in quite the same way so I really wouldn't worry about the exact meaning of your FSH levels!
Also a single blood test cannot be relied upon and there are other hormones involved too that are not measured, as well as your ovaries partly doing their own thing in the background, and partly being affected by the HRT!