The thing I read showed it tended to double about every 3 days...
This is correct. You can spreadsheet it yourself.
89 cases on 3/1
Multiply daily by 1.30 (it's actually more than doubling by a smidge)
You get 1226 cases on 3/11 (we're actually at 1285)
1.3^3 = ~2.2x every 3 days
At that rate, we have
- ~6000 cases by St Patties' Day
- 250k by the end of the month
- 1M by about April 6th
- >2.5M by April 9th
We'd have >10M by Tax Day.
So, either you start quarantining people in large numbers now, or that's where you end up in about 1 month. Again, that's not being "alarmist"; that is epidemiology math.
That said, the expected doubling time is 6 days, not 3. So some of this may be 'catching up' on testing. But if you do nothing, the math is the same, it just takes a few more days to hit those numbers.