When Can I Breed My Chihuahua After She Bleed?

You should hold off until you know the answer to that and a lot of other questions. Creating lives you are responsible for is serious as is risking your girls life. Is this at least her third season and she isn't a very tiny chihuahua? You know that they are prone to difficult pregnancy, whelp and nursing periods and often need c-section and are prepared for all that and know about all those things? You know the main contributors to future shelter pups and intend to take steps so your pups are less likely to end up there? You don't want to breed until you know about breeding (which is complicated) and missing a season (or more) is always worth it. You want to make sure you aren't following BYB/puppymill practices (and therefore earning the title as well as the end results) and are taking steps to be a good breeder before you breed.
Here is your breed parent club and you may want to look into a mentor or two to help you with everything along the way and some information and links and resources on breeding and whelping to get you started. Good luck.
http://www.chihuahuaclubofamerica.com/ q3525724.html#a2810229
q5762034.html#a2906893
http://www.wildheirlabradorrescue.org/readingroom/what-is-a-back-yard-breeder.php  
http://members.tripod.com/antique_fcr/goodbreeder.html