Usually it all goes back down. A lot of women who weigh daily notice a trend in their weight related to their menstrual cycle, but the general trend (if they are taking in less calories and moving more!) is down. If you're concerned about it, I would try tracking daily and looking for trends.
The only issue I'd foresee where you don't have a net loss after the water weight goes away, is if you tend to binge eat or eat unhealthily during your period.
Started Jan. 2013 | Mini Goal 1: Onederland - Reached 5/20/14| Mini Goal 2: 179 (no longer obese)