Diagnosed at 39 + 5 days!!

Hi all. I'm UK-based, and this seems like a very American sub, so I'm just saying at the start that my care might be different, but I'm putting it out here anyway, just in case.

So, I had routine work done as my baby was measuring big last week, and my results came in today that I apparently have GD.

I did have a glucose test around 10 weeks ago, and that all came back perfect, so this must be a recent development. No symptoms, so I can't narrow it down.

Anyway, the point is I'm now at a loss about making a decision on next steps. We've had a LOT of issues with the measuring scans, so I don't put much stock in how big my baby will or will not be. Basically, mine looks like a yo-yo because every sonographer apparently measured the baby differently. Last week was like 90%; it's been down to 50% previously and everything in between.

Previous to this, we were heading for zero risks beyond me being ancient for a baby (35 years young 🙄). So I've not really had to think about much. It was just going to be "baby gets here when they get here" and no medical intervention. I'm now being asked about being induced and C-sections. But I'm just totally lost because everything has been perfectly fine, and no one had concerns before now. I appreciate that GD causes complications, but surely if there was anything actually concerning with the baby, they would have picked this up already through other testing?

Sorry, this is a bit of a ramble. But at this late stage, I'm just very confused and feeling there's a time crunch on how quickly I need to make decisions, so I'm looking to see if anyone has any similar experiences.