Sounds about right. Keep it up, keep burning the pounds, and when Spring rolls around, sell the exercycle and get a bike, you'll be ready.
Re: the knee, it may just be adaptation to the workload, but, set your seat so that at maximum extension, your knee is slightly bent (not "locked") and your ankle position is neutral.
Knees are sensitive to seats being too close to pedals. If you extend too far from the pedals, on a recumbent, that'll tweak your lower back. Somewhere in the middle is your comfort and efficiency zone.