After a partnership has bid three suits, it is unlikely that the fourth suit is the best fit. Therefore, you can usefully play a bid of the fourth suit as an artificial force, asking partner to describe his hand further. The bid does not promise any particular holding in the bid suit. Traditionally, fourth-suit forcing is forcing for one round only, though it is becoming quite common to play it as forcing to game.
No natural bid describes your hand: 3NT is very risky without a stopper in the unbid suit; both 3♦ and 3♣ are underbids as well as overstating your support for partner; 3♠ is also an underbid and overstates your spades. The fourth suit bid of 2♥ is perfect.