In Act 3, Scene 5, Romeo and Juliet's final words to each other are:

Juliet: O, think'st thou we shall ever meet again?

Romeo: I doubt it not; and all these woes/ For sweet discourse in our time to come.

Juliet: O God! I have an ill-divining soul!/ Methinks I see thee, now thou art below,/ As one dead in the bottom of a tomb:/ Either my eyesight fails or thou look'st pale.

Romeo: And trust me, love, in my eye so do you:/ Dry sorrow drinks our blood. Adieu, adieu!

One would think that with all their exciting plans for the future that the lovers would be full of anticipation, but it is obvious from Juliet's "vision" of Romeo in a tomb that Shakespeare is foreshadowing the lovers' fate.  At first Romeo tries to assuage Juliet's sense of foreboding, but when she mentions her vision, Romeo, too, admits that he sees Juliet as "pale" and instead of being filled with passion, he mentions "dry sorrow."