Hi again everyone, finally had a chance to RTFT, which I hadn't done last night when I just skim-read and was half-asleep and typing on my phone keypad etc.
imnotalone - I have read your first post and can see why you say we have a similar story. I am convinced I had GD in both of my first two pregnancies, DC1 was very puffy when born, as was I for the last few weeks of the pregnancy, and I distinctly remember I was always having ++ in my urine (sometimes glucose, sometimes protein) - I assume that because it was not consistently there, that must be the reason I was not even GTT-ed in my first pg, but in hindsight, it seems pretty negligent, considering I had a 10lb 6oz baby, severe shoulder dystocia with resulting (temporary, thank god) injuries to both me and my DD.
You'd think they'd have been more on it the second time around - tbf I did have GTTs at 28 and 32w, and a scan at about 30w I think (which predicted 8lb baby...), but I know I had anomalies in urine testing after the second GTT, as I remember telling my MW that I had that the first time around too and I joked about it. She didn't refer me for further testing. DS was 11lb, and I did suffer shoulder dystocia again, but this time around I was not on epidural, I could feel everything, which was hellish, but also helpful, as I think the combination of that, with the fact of it being my second birth and my body had been there before, meant he was only stuck for a minute or two at most, and neither he nor I suffered any injuries as a result. I consider it by far my most magical birthing experience (not those two minutes, though 
) , and feel so lucky I could have one of my three naturally.
TBH I thought my MW for my third pg was being a bit ott when she wanted me to take another GTT when glucose showed up at 35.5w, since I already had a C-sec booked for 39w, and the GP surgery couldn't fit in a GTT til I was 36.5 (this still pisses me off, in hindsight - a full week without treatment at that stage of pregnancy, when a GTT is so easy to administer). I took the GTT at 36.5 and then early the next morning the hospital called me and wanted me to come in that day, and the rest was a whirlwind - I saw about 8 different people on that day, and the result was I was on insulin immediately, a plan was made for a C-sec at 38.5, to give a full two weeks for DC3 to reduce glucose dependence, but I was told that GD babies are at an increased risk of pre-natal "problems" ( I don't want to write the word in case others haven't actually been told this) so I was freaking out, big style.
HOWEVER, DC3 was absolutely fine, they tested his glucose levels (but only at my insistence! Unbelievable, no? All that to make sure he wasn't glucose dependent, and then they only tested him because I kept on at various midwives that no one had tested him etc.) a few times in the 24 hour period and they were normal. He was pretty big, I suppose, though I refer to him as my titchy one after the size of the other two...
Sorry that's loads to read so I hope you really did want experiences OP 
heartisaspade have you been given a blood test to determine when onset occurred? I can't remember what the test was called - something like a retrospective, but apparently it quite accurately could say when the GD started. It was quite reassuring for me to know it had only been a few weeks (though I sort of knew that from my 32w GTT, it still reassured me).
Also, as a general note, growth scans are notoriously rubbish. Mine was a full 3lb out with DC2. Much better indication is previous baby size.