Yes mate, had same thing with my Akita when he was a pup. Vet told us he had a severe heart murmur and i almost took him back to the breeder. He seemed perfectly fine to us so we left it, when he got his first yearly booster around 14 months old i asked them to check his heart and Vet said all was perfect.
He lived to a good old age, i only had him PTS in May this year
Some pups hearts just take a little longer to seal off than others, give it time and see if yours does. I'd say by 4-5 months his heart will be perfect