Frustration with NHS and medical system in UK

Not that this will help, but when I had my first, when I thought I was having contractions (I was) I was told I was just overreacting & "that's just how the induction feels sometimes." Begged and begged for someone to just check on me, and as they did i went into active labour. When I told my midwife about it because it's a concern of mine this time around (as I'm being induced again) she said "yeah that is one thing we aren't very good at."
Absolutely no faith in them at all. Outside of pregnancy they held onto a possible diagnosis of coeliac disease for 8 months, after telling me all my results were normal so I was in agony literally eating food that was KILLING my intestines for nearly a year and only told me my results WEREN'T normal after I chased them again after a particularly bad flare up.
You're defo not alone.

Speak to PALS at your local hospital

Everywhere has different guidelines and NHS just doesn't routinely test for GBS, there's probably lots of other things that it doesn't routinely test for as well 🤷🏼‍♀️
I do agree though that the NHS is definitely far from perfect!
When they test urine they test it for glucose, protein, leukocytes and the PH level. If any of those indicate an issue, eg high leukocytes indicating an infection, then it goes for further testing so they can identify the issue. Or that's what they should be doing anyway, if they're not then that's an issue!