I have a 3 1/2 year old female GSD She is in excellent condition weight and upto date on shots worming heartguard and frontline. She has her certifications also. She has been bred 2x so far do I need to skip and how often.

You'll find different opinions on this, but reproductive specialists will tell you if a bitch is in good physical condition it's more dangerous to skip a heat than it is to breed. Meaning you shouldn't have to wait.

Personally I've never bred a bitch more than twice before having her spayed. A breeding program should be progressive, moving from one generation to the next. Not repeatedly breeding the same bitch. You don't make any progress that way, you're just churning out puppies. And, IMO, the goal should always be to improve the quality of the breed, not just to make more puppies.

Now, you say your bitch is 3 1/2, and she's already had 2 litters. She was bred too young. I don't breed a bitch before she's 3. Some genetic problems don't become apparent before a dog is about 3, like idiopathic epilepsy.