I'm assuming thats the normal when the pads are going...
Almost certainly.
How long can I go before replacing? 1-2 week of normal driving?
Depends on how many miles you're normally putting on. Basically, you want to get them changed as soon as you can, since that squealing means that the metal tab is contacting the rotor. But you don't have to park it until then, just get it done as soon as it's practical for you. Don't put it off though.