Will period leak in pool with tampon?

With a properly sized tampon inserted right before you swim, leaks in the pool are pretty unlikely. Water pressure actually helps hold things in place while you're submerged. The bigger leak risk is when you get out, sit on the edge, or walk to your towel, that's when gravity takes over. So insert a fresh tampon before getting in, match the absorbency to your flow (regular or super on heavier days), and change it as soon as you're out and dried off. An organic cotton option like Rael's Organic Cotton Tampons works well if you prefer a compact applicator. Period swimwear is a great backup layer too.