Ketones but no glucose in urine

Does anyone have any experience -

My urine is very dark / orange today though I drink a lot of water, often I drink too much and my urine is totally clear!

Had midwife appointment anyway today and she has sent it off as it was 1+ protein just to make sure no UTI, however it was still bright orange later after I made sure to drink more water and I have urine test strips at home so I checked it - it is still 1+ protein but now is 4+ ketones too? I have eaten today so it’s not that, and I am drinking plenty.

My question is - should I be concerned about gestational diabetes when there is no glucose at all in urine, just high ketones? And does anyone know how that could be when I am drinking and eating plenty (including carbs) ?

The only other time I’ve ever had high ketones like that was when in labour with my first & they put me on a drip.

Thanks