how much blood is normal?

for the past couple of years, i've suffered with UTIs every so often. always starting very suddenly and containing a lot of blood - as though i'm having a period.

they always begin late at night, so when i call 111 they advise me to wait until the morning to get antibiotics, by this time there's no more visible blood.

this got me wondering if the clinicians understand how much blood i'm talking about, as whenever i've taken a sample the following morning, it only shows microscopic haematuria.

just wondering if is this is normal? i'm 22F.