I had a heart cath that showed no blockages. does that mean i'm out of the woods for heart attack?

Yes: Unless you use Cocaine or have a very, very rare condition (because you can never say "never" during this lifetime!), you're out of the woods and, if you're having chest pain, it's due to something else. Odds are 99.9% that you're fine.

Probably: The absence of blockages is very good. However, this does not mean there is no atherosclerotic disease. It just means there is no narrowing. Though highly unlikely the disease could break away suddenly and cause a heart attack (ruptured plaque). You must have risk factors and symptoms to have been cathed at 37. Control of weight, diet, exercise, smoking, etc are still very important for you.