I would. Even if your stitches look good, they will look better after blocking. There are several methods you could use.
1) Wash, rinse, shape it, pin where necessary, leave til bone dry.
2) Pin down, lay damp towels on top, leave til bone dry.
3) Pin down, heavily mist, leave til bone dry.
Is it already seamed?
I block the pieces first (whenever possible).... then seam.
For the Tempting II summer top we're working on...I couldn't block as normally.
I laid down a wet bath towel. I placed Tempting II on top of it. Then I laid another wet bath towel on top of Tempting II. After a day, I removed the top towel. And now I am waiting for the bottom towel (and Tempting II) to become bone dry. My stitches are already beginning to perfect themselves!
This is a photo of Tempting II, after the top towel was removed.
At this writing, Tempting II is still sitting out there on the still damp towel. It will probably be dry by Monday. I'm in no hurry.