Swimming on period question? Read description.?

Tomorrow I have to go swimming, I've had my period for 7 days now, and I have a super light flow now. But randomly blood comes out every so often. And my mother wont allow me to use tampons and refuses to buy them and what not. My bikini is black, and I'm planning on wearing long black board shorts over it as well. Will it be safe to go in? I know It's gross and will contaminate the pool, but I have no choice, and I don't think I'd want to wear a pad in the pool.. Lol Doesn't sound so helpful since It'll absorb the water anyways. Will the blood like float out from my bikini or something if it randomly comes out? Please help.