I do close to the same thing. I'll lose about a pound the week after my period. The next week, that weight loss holds steady. About the third week, I actually start to see a rise by the end of the week (sometimes a couple ounces - sometimes, like this month, a whole pound). Then, the day after my period starts, which seems a weird time compared to every one else, I have a huge woosh. All of weight loss woosh generally doesn't hold, but most of it does. I feel like I lose weight at a slower rate than most girls my age (24) and weight, and so adding those waiting periods on top of that fact can be a little discouraging. Still, this didn't bother me too badly until I actually joined a challenge here on 3fc. I'm up this week despite a ton of hard work, and putting that in the chart blows.
Mini-Goal #1: 220 - Achieved 09.17.12
Mini-Goal #2: 210 - Achieved 01.03.13
Mini-Goal #3: Onederland!! - Achieved 03.26.13
Mini-Goal #4: 189 - Achieved 07.25.13
Mini-Goal #5: 179
Mini-Goal #6: 169