Double is a good start - you have a strong hand and are playable in three suits. If you overcall 3♥ immediately, then you could have a weaker hand than this and will probably end the auction, you remove two potential suits from play, and partner will probably not have enough in the minors to bid three no trump when it is right. Your plan should be to bid three hearts over most of partner's bids. Although many will think that this implies six, the general expert method is that this is a 'strong and flexible' bid - implying a hand too strong to overcall, perhaps still interested in partner's suit (when he has bid one), showing 5+ hearts. The corollary from playing 'strong and flexible' is that single-suited hands try to find an overcall at an appropriate level rather than double, or make it very clear what they have after the double. For three no trump to be right, partner probably needs a double spade stop or nine running tricks. With finesses likely to fail, and limited points opposite meaning nine running tricks are highly unlikely, it is worth investigating other contracts. Cyberyeti said the same in shorthand :)