Beer or not that is just a normal weight fluctuation.
You should avoid all alcohol if you are focused on fat loss. It shuts off fat burning just like white sugar can and then you have to work through pulling down that blood sugar and then burn off any excess calories that came with that, plus carbohydrates retain more water in the body per gram than any other macro nutrient. Beer affects your ability to absorb nutrients and a well nourished body will tend to shed fat and keep fat off more easily. (best nutrition = best state of body)
Not all beers are created equal. Look into some healthier beers.
The good and bad:
Realbeer.com: Beer And Your Health
Talks about vitamin depletion and how the blood sugar crash can give you the munchies.
http://www.mensfitness.com/nutrition...-the-body-good
Just more reading with a guide to finding your beer.