Glad the kitty seems to be fine otherwise.

Your vet's response has me baffled. Blood in the urine is never 'normal', she/he didn't want to see the cat but prescribed antibiotics anyways for something she/he deems as possibly normal????

Maybe it's just in the way I'm reading it but that sounds so weird to me.

Anyways I hope the bloody urine goes away and never returns (the blood, not the urine lol).