It probably won't take 4 weeks as we already have 1000 in LA, 200 in Atlanta, and smaller spotty numbers in other areas.
Unless the US gets tougher and allows these people to self isolate, it will spread. How closely are they watching these people to make sure they are staying home and away from others? I don't trust that.
Hence, a good three weeks of stuff in my house to stay locked in if it comes to that. If not, there are just some things I won't have to buy for awhile.
I refuse to worry at this point
and I'm still doing what I normally do, but remaining vigilant.