I am thinking that might be an umbrella magnolia, the flowers seem consistent but the size seems big, it does look like the tree is a couple of years old. I am not certain where you are geographically or when you are seeing the flowers, if it is just in the spring or early summer it might very well be a magnolia, this breed has flowers that are not as nice as the magnolias we normally think of. I have had one for years and I am in New York, it is wonderful when it flowers, they remind me of orchids but very fragile and short lived. after that just leaves and like a very small brownish bud where flower was. I would say it is a mid sizes tree.
Now if it flowers in the summer till fall, (consistent flowers right up the stalk) I am going to say that's a young Bean tree which is a catalpa, now I know you said it isn't because you have some already but I wanted to tell you, I have a big one and when you let the beans grow they really do look like this for quite a few years, they do not bean out for at least 3-4 years or more. Not trying to argue just wanted to share that because I get them cropping up randomly.