Can I swim?!?!??????????????????????… Womens health?

I'm on my period and I started Sunday. Sunday was heavy so was Monday but today is lite. Like when I go to the bathroom only a little bit is there. I've been franking so much water it's crazy to make it light. That's what my doc. Said. So am I ok to swim without tampon? I'm not wearing tampons cuz I don't like em. But doesn't ur period stop in water?