I don't understand what the deal is with testing (lab capacity?), but no matter, after six months we should be seeing testing increasing rather decreasing.
My son's childminder has tested positive, so we (me, wife and son) are isolating at home (although to be honest my son is the only one who actually has to isolate). Until any one of us develops symptoms though, we are not entitled to a test, which I find odd. Particularly in my son's case as he's been in close proximity with a positive case for several hours at a time.
Fortunately no symptoms from the three of us so far though.