It's normal to have some weight gain before or during your period due to hormonal fluctuations, water retention and food cravings. Generally, it will go away a few days after your period starts which seems like you lost weight after period.
All the teas contain some amount of tannic acid which in combination with our food reduces the absorption of iron in the body. So, drinking too much of it during periods may not only lead to malabsorption of iron in the body but may also cause headaches, irritability, insomnia, anxiety, restlessness, nervousness due to the caffeine present in the tea.
Having a lot of dairy products is not the best idea, as it can cause cramping. Dairy products like milk, cheese, and ice cream contain arachidonic acid (an omega-6 fatty acid), which can increase inflammation and can intensify your period pain.