In the last 6 weeks, I have noticed that the scale only moves every 2 weeks. So every two weeks I lose at least 3 lbs.

I'm not too worried because my inches are declining every week, so I don't get too stressed out. I can now definitely see the pattern of a 2 week cycle.

Has anyone else experienced this and is their a scientific reason for it?

Yep, I see that regularly. I didn't when I started losing but during the last couple of months it's been 2 weeks nothing then 2 weeks of whooshes. I suspect the reason for it may have something to do with TOM for women.

It gets discouraging through the 2 weeks of nothing, but it's the end result that matters.