Swimming while on period.

I'm personally a big fan of a diva cup if worried. But I haven't tried to swim without something in years so I'm not much help

Yes of course you can still swim! when your in a body of water the flow of your period slows down and since your already having a light period it shouldn’t be a problem.

I used to swim a lot while on my period as a teenager (I don't really have to worry about it much anymore with my birth control). Like Desiree said, you're period will slow down/stop while you're actually in the water. I speak from experience when I say designate a "period bathing suit." Usually it's one that's cheap and very forgiving in case you're dealing with period bloat. That way if you plan on keeping your bathing suit on for a little while outside the water and end up staining it a bit before you can make it to the bathroom, it doesn't matter.

I’d suggest using a cup or disc

My period was always light so I didn't like tampons either, and I was fine with a thin panty liner (not the padded ones) in a tight swim suit. I used a diva cup before during heavier times, and it's better than a tampon, but kinda difficult and inconvenient to deal with. Honestly, I can't remember ever actually bleeding while in a pool. It's like my body won't let it happen lol I'd say if you are super worried, maybe you could try some period underwear under the suit?