Can i purchase a handgun here in California if i am a certified medical marijuana patient?

I already own a shotgun (not permit required) but if i want to go purchase a handgun will i run in to any problems with the local federal and F.B.I background check? I got a medical marijuana license recently and would love to hear from law students or lawyers on what you think and or know. Plus, would i get in any trouble if i owned my shotgun then got a medical marijuana license afterwards? I'm trying to follow the law to avoid any problems or incidents. Thanks everyone....

: http://alcoholdrugstreatment.info/can-i-purchase-a-handgun-here-in-california-if-i-am-a-certified-medical-marijuana-patient