Very possible; the only difference (and I'm sure someone can tell us if there's a significant difference in the 'spreadability' of Covid Vs Flu) is that everyone in the household has had symptoms within a week of one another which has never happened previously
And maybe that the range of symptoms is wider. Very mild in my case. Just seen Idris Elba has tested positive - has no symptoms...how the fuck did he get tested then? It's not like 'fancying a Cherry Pepsi Max' "Oh, I feel fine but fancy a Covid-test"
Seeing as the UK has tested 44,000 and only 1,500 have been confirmed as covid-19, you more than likely have got the normal flu.