I do! In my first pregnancy I put on about 18 lb in total. DD was born two weeks late at a very decent weight of 7lb and very healthy! This time round, given that that model seemed to work OK for all of us, I am pretty determined not to put on more than 18 lb and have been monitoring my weight throughout. I never go hungry and I eat a healthy diet, but I weigh myself every day and if I seem to be putting on weight a bit fast, I do take extra care for a day or two.
I suppose you could say that I am actively regulating my weight. To me, there's one quite good reason for this, which is that I have to work up to my due date (and probably beyond!) so really really don't want to get too big. Also, I really can't be arsed to go on a diet afterwards.
On the few occasions I have admitted this to anyone other than my husband, I have been treated to very great disapproval! The implication is always that I am potentially damaging my baby or even my own health. I am sure that I'm not, but it seems to be totally taboo to admit to doing this. The only reason I DO sometimes admit it is that people have a tendency to say, "you're so lucky, you don't put on weight blah blah, it's so unfair", and I sometimes think it's only fair to point out that in my case it's partly down to conscious effort.
Anyway, IS this a taboo subject do you think or am I just being weird? And if it is, is it just because I'm seen to be letting the side down because lots of people enjoy eating what they want during pregnancy? In which case, I totally understand the reaction and I admit here and now to being an obsessive control freak!