I wouldn't worry about it too much right now. Just be careful with him - don't let him jump from high places, run a lot on pavement, or do anything else that might be hard on growing joints. Keep him lean and make sure he eats a proper diet.
When he gets a bit older, you can do x-rays. I think you can do preliminaries as young as 9 or 10 months (maybe younger, I don't really know) but their hips will keep changing as they keep growing until they're about 2. X-rays at 2 or older will tell you, for sure, whether or not the hips are dysplastic.
Even if he does have hip dysplasia, that's usually not a death sentence. Lots of members here have dogs with varying degrees of dysplasia. Often the dogs won't even have pain until they're in their later years, when they start getting arthritis from it.