fabulous@fifty

Your weight can, and will, fluctuate greatly from day to day. For instance, Water retention. If you've had more sodium than usual, you could be retaining considerable Water weight. Muscle is more dense per inch than muscle thus weighs more. If you're building muscle, you could gain a couple pounds despite losing inches.
Honestly, I know it's frustrating. When my weight does a random fluctuate I usually stand on the scale going "WTH just happened?" But if I just give it a couple days, that random weight fluctuation resolves itself and takes a pound or two with it.
Hang in there, you're definitely back on the right track.

I agree with Missy. My weight fluctuates 3-4 pounds everyday. It's usually due to Water retention. That is why I am trying to get away from weighing everyday. It isn't a good measure of weight loss. Once a week is plenty. However, it usually does correct itself. You can help by drinking lots of Water and keep up with the exercising. That will help you body let go of the excess water.
Also, 20 pounds in 1 month is AMAZING!! You should be proud of that!! Your body is basically a machine and sometimes, it has to recalibrate itself. So, after loosing that much weight, your body is rebooting and moving stuff around. That can cause a temporary weight gain. I seriously doubt you gained 3 pounds of fat. It's probably just your body readjusting. Mine has done it numerous times throughout my weight loss. I will gain 5 pounds one week and the next, it's all gone plus 2 pounds. It's completely normal and nothing to fret over. Just keep doing what you are doing and it will correct itself.
Again, big congrats on getting back on track and with the 20 pounds. It makes my little 5 pound/month weight loss seem petty. LOL Best of luck to you!!

I know the feeling, it truly makes you wanna skip the whole process, but when you think about light at the end of the tunnel you're reminded why you started this journey in the first place. I can go on and on about Water weight, muscle vs. fat to explain the weight gain and as logical as it is it doesn't make you or any of us feel any better when the numbers on the scale go UP.
A week and a half go, I got on the scale, log my weight, had my band adjusted ate properly, exercised 3 days out of 7, got back on the scale the following week and had gained 10 freaking pounds. So trust me when I say, I feel your pain. I encourage you to hang in there, keep your head up and keep doing the right thing and it'll all pay off in the end.