I just had a baby may 21 at 22 weeks 4 days but he died 2 hours after birth when should I try again

First your going to need to give your body a chance to heal. You may even start to lactate. You body doesn't know what really happened and its going to go through the normal steps.

Sorry for your loss.

So when to try for another baby

Its best to follow your gynocologists advice. The reason being is that they would be aware of your situation. At a minimum I'd say wait at least until you have 3 complete reguler cycles before trying again.