Ok..so I started my diet Jan. 6th 2006. I've lost a totel of 39 pounds. Im been eating right and exercising like crazy. But this last week I put on 4 pounds. I dont understand why. I have been sticking to my diet and I even exercised more then normal. I am lifing weights and I did have my monthly cycle this last week. Could that have something to do with it?

I would never let a one-time weighing get me down. Too many variables. Pick up a glass of water, it's heavy. If you drank that glass of water, you would weigh you + weight of glass of water.

I look at trends over time to determine my weight.

you lost 39 lbs in 3 months??? wow! congrats!

don't worry about the 4 lbs. it could be anything- like water-retention from salty restaurant food. wait a week and see what happens. but the general trend is most important.

water weight is a huge factor for me. It comes one day, and then leaves another.

You may be gaining muscle as well. Muscle weighs more than fat so that's why the scale went up