Most founders in this situation bootstrap (use their own cash). Many use credit cards for an instant 0% loan for 1-2 months.

If an unfunded, pre-revenue startup can't get cash from founders, it's dead. A startup is dead when it has no cash. I meet a surprising number of people who don't realize that someone has to fund you -- you're not going to raise money on an idea alone.

i get you, startups need to survive pending when they get the cash in (funding or revenue).