up and down

First, the best thing to do is not weigh yourself daily. It becomes obsessive, looking at a pound or two here or gone. Secondly, weigh yourself in the morning when you get up for the most accurate weight, or at least same time every day. And third, yes it is normal to flucuate, between 3-4 lbs. due to water shifting, etc. So don't sweat the small stuff!

It usually depends on what you're wearing and what time of day you are weighing yourself. You could also be carrying a lot of water weight. If it stays in the same range all the time then I wouldn't worry about it. Otherwise maybe you should check with your doctor.