Congrats on your loss so far!!
Welcome to the wacky world of weight loss! It actually sounds like everything is normal! Weight loss isn't linear -- our bodies have lots and lots of ups and downs (remember the scale isn't just weighing your FAT, it's weighing all of you, including water, which frequently fluctuates). Most people weigh less in the morning than later in the day. The general advice is to weigh at the same time and under the same conditions each time and use that number as your benchmark.
Because of the frequent fluctuations some people don't like seeing all the ups and downs, so they weigh weekly.
We don't generally consider people to be at plateaus until they have been at the same weight for a number of weeks!
For more info, see this great thread on scale fluctuations.
Fluctuations in Scale Weight and Water Weight
So, my advice -- be patient and if the fluctuations bother you, weigh weekly!!