I just wanted to go over a defensive decision that all Zerg players should make part of their Starcraft 2 decision-making toolbox.
The subject today is bunker rushes and proxy barracks / gateways. If you open with a hatch-first or early-hatch build with Zerg, YOU NEED TO CANCEL IT when you scout a lack of Gateways / Rax in the enemy base.
Immediately throw down a pool if not already started, and you NEED to get a spine crawler up. I also recommend Roaches over Banelings, because early banelings can be kited and killed by good marine micro, and Roaches use less Larvae, which you will be severely limited on. Roaches are surprisingly good against small numbers of un-upgraded marines. But again, it's more about the larvae, so make sure to build a Queen, or replace her if you lose her. However, if you are really tight for money, build 2 Roaches instead of 1 Queen. However, chances are, with no Queen and only 1 Hatch of larvae, you will have plenty of minerals to build Queens with.
If your opponent is NOT all-in (and most proxy rushes are), you can't afford to just make spines and be contained, because your larvae count will suffer. Make sure you check just how many marines your opponent continues to send to your base, even if he dares not attack because of your Spine Crawlers. If he expands and doesn't keep building marines, you need to bust out ASAP, and either expand yourself or counterattack.
Counterattacking is always a good strat (if you manage to get units out of your base), because without his early barracks / Gateways at home, he won't have a wall-in. Even a few Zerglings, if you attack when he's also attacking your base, may go undetected long enough to kill a LOT of workers.