Hi, yes that's been almost exactly my experience as well. At least as much as I can remember. My longest Water Fast was 14 days, but that was about 7 years ago. Since than I've only done about week long ones. I've always been and felt so much better overall after fasting and so do it about once or twice a year.
I've been reading recently about the potentially amazing benefits of going as long as 40 days, and sure would like to try this sometime! It would be such a commitment though, as working when fasting can really be a drag. Ideally I'd love to be out in nature somewhere beautiful, with books, guitar, pen/paper and time. ;)