not sure if puppy is sick or just a puppy

[smatana1]

About 3 weeks ago we got a puppy that is 6 months old from my husbands friend that could not keep him any longer. He has been great most of the time. The only problem that we are having is peeing. He seems to go to the bathroom all the time. I take him outside priase him for going the bathroom and we come in. About 10 min later he pees in the house. I even stay outside for a while to make sure he is done, but he still some in and pees. The man we got him from said that he was house broken and he does have all of his shots. He goes out about 5 times a day and pees everytime, but he also has about 4 accidents in the house a day as well. I am going crazy. My older dog hides most of the day because she knows that you cannot pee in the house!!!
I do not know if I should take her to the vets or just let some time pass and see if he hets better. Thanks nicole