That is a Japanese (or Kousa) Dogwood - Cornus kousa
. This species of Dogwood blooms after the leaves have emerged, rather than before like the native species Cornus florida
This is a very nice tree to have in one's landscape, not only for the flowering you see but also for fruit characteristics and generally excellent fall colors with oranges, reds, yellows, and burgundies in its repertoire. It is not small, but can slowly reach dimensions of 20 feet tall by 20 feet wide - or possibly greater given high quality growing conditions. Depending on where you are in Massachusetts, you should visit the Arnold Arboretum in Boston and see what mature Kousa Dogwoods can become. I think you will be impressed and pleased.
As mentioned in this thread, prune slowly but regularly to remove branches that will eventually be in conflict with where you want to be able to walk. You can cut back part of a branch at a time, and take several seasons to fully remove a whole branch. Fruit will form, but not drop until fall. It is such a good plant, I think you will overlook any temporary inconvenience that any fruit might cause. It also happens to be edible; you may develop a taste for its fruit and compete for its flavors with any pesky wildlife.
Here's some idea of what your tree may aspire to: