It sounds to me like one of those random blips on the scale -- your calories and exercise are great, so it could be in a few days you will have a woosh and see those lbs slide away. Are you drinking enough water? Drinking enough water will actually help you *not* retain water, strangely enough.
One thing to think about -- I find that I get bloated mid-month, maybe even more than at TOM. It's an ovulation thing, I guess. I don't remember this always happening, but obviously our bodies change with age (and in my case, I had my third baby last year, and I think this mid-month bloat started when my period came back after breastfeeding).
Lastly, it might help to switch up your exercise a little -- try a new machine at the gym, or a different pattern to your workout (like a new setting on your usual machine, etc).
Hang in there!