Not too early for peas. In fact, you may even be a tad late for peas (I'm in Boston and planted mine a few weeks ago).

But too early for beans. Or at least it has been my experience that they just sit there if the ground is too cold. The old-fashioned way of deciding if it's warm enough to plant beans is if it's warm enough to sit on the ground. If your butt is too cold, it's too cold for beans. (I've never planted corn, but I think the same goes for it.)