You will lose this weight in a week following the menses. This bloating and weight gain is due to hormonal fluctuation and water retention. Monthly variations or fluctuations in weight are common during the period; therefore, it is better not to weigh during this time to avoid confusion and unnecessary anxiety.
You're weighing yourself after you shower. Keith Kantor, a leading nutritionist and CEO of the Nutritional Addiction Mitigation Eating and Drinking (NAMED) program. “After a swim or a shower, your body can absorb 1 to 3 cups of water, increasing your true weight by a few pounds.”