Yep, Bailey was diagnosed just before 6 months, and was given an extra month to see how the bone was growing, then put in a brace for 6 months (until 13 months).
He had no obvious signs (no uneven leg creases or clicky hips), it was only that he also happened to be very low toned so the paed ordered xrays and the hip dysplasia showed up.
Its pretty uncommon with boys

Lets us know how you get on OP. Like PRMG said, it probably is nothing x

ETA - I was told that at that age the treatment (brace) is generally for as long as they are old, itms, as they have layed down a fair bit of bone by then and need to correct the bone growth