H1 B extension in progress,can dependant travel?

Hi,

my husband h1b visa is valid till 30 sep 2013 and visa extension is in progress.we have the receipt number and it shows - visa extension is in initial review stage in uscis site.i have not yet gone for h4 stamping and planning to go soon since i want to join my husband in US

want to know if i will be allowed to stay in US even after 30sep '13?