Of course, with no test, people could have had it without anyone knowing.
That raises an awkward question about how we managed mass transport to work, gigs and football matches without a "peak" of the disease occurring - instead the peak is happening after a gradual ramp down of gatherings.
Which is because of the incubation period, no? So all of those people who were out in pubs last Friday night will likely only start showing symptoms over the next few days, and those that will need hospitalising are still a week or so away from that. We won't see a slow down for at least another week or two, as these measures will have about a 2 week lag in terms of the number of people who get seriously ill.