Just wanted to give a heads up, I had DS tested on Wednesday at lunchtime in a drive through centre (his school bubble burst and PHE advised PCR tests for all), but still hadn't had results back at lunchtime today (48hrs). I called 119, his test hadn't been registered, so we did that over the phone, and I had his result texted to me seconds after hanging up (negative thankfully).
Very glad I followed up, and thought would spread news if you're waiting on tenterhooks as I was. He still has to self-isolate for the prescribed period, but the rest of us can safely carry on as normal.