Sometimes. We've had a lot this week!
Ours this week (as a family we've done 8 so far)
First set, 4 tested, three back in 18 hours (one pos, one neg, one inconclusive) and one back in 30 hours, negative
Second, inconclusive retest, 43 hours (negative)
Third, symptomatic test, 34 hours (positive)
Fourth (retest for the two of us yet to succumb due to household contact ) 30 hours, both negative
That's it for us now I hope, unless my son or I develop symptoms.