On the first day of my period, with a special menstruation swimsuit, can I go in the sea?

Okay, so yes you totally can go in the sea on the first day of your period if you're wearing a period swimsuit! That's literally why they exist, so you don't have to miss out on swimming just because of your period. A period swimsuit has a special built-in layer that absorbs your period blood, so it won't leak into the water. It's like wearing period underwear, but for swimming! They come in all different styles and absorbencies, so you can pick one that works for you.

It's super important to make sure you get one that fits pretty snug around your legs and waist so it can do its job and catch everything. Once you're done swimming, it's a good idea to change out of it when you can, just like you would with a pad or tampon, and then rinse it out. Then you can wash it properly later. No biggie.

Some people also use tampons or a menstrual cup for swimming, even if they aren't wearing a period swimsuit. It really just depends on what makes you feel the most comfortable and confident, and what works best for your flow. The main thing is to find a way to stay active and do what you love, because your period doesn't have to stop you!