Yes, it happens. I'm 12 weeks in, and I have weeks where my weight doesn't budge for days at a time. I sometimes have a week where I only lose 1/2-1 pound, then the next week I lose 4 or 4 1/2 pounds. Hang in there, and you will probably drop a couple pounds suddenly in the next few days.
Someone here has a quote on their signature that says something like we use the scale because it's easy, not because it's the most accurate way to track progress. I would definitely recommend you take your measurements, too. If I'm not losing weight, I'm often losing inches.
Make sure you're drinking all your water, and them some!
Keep up the good work!