According to a post on the tenforums.com the update has been delayed due to "new found problems".

FWIW, I have the 1803 version on my Windows Insider installation. 

The updates for the Insiders fell apart.  The first update would install and change the version number but then it would disappear from the listing.  I was up until 1:15 am and did two clean installs to try to see what was happening. 

After my second clean install, I am set with the first Cumulative update.  When they get that mess straightened out, maybe we will move on.

There is a twitter thread somewhere mentioning the 10th was a Microsoft internal number for the public release.

If anyone is wondering, the replacement or renamed build (17134.1) has been released to the Insiders.  How long it takes to go public we do not know.  It might even be as early as today or hopefully, before the end of the month.

I got the update this morning.  So far, no problems.

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@Saltgrasswrote:

If anyone is wondering, the replacement or renamed build (17134.1) has been released to the Insiders.  How long it takes to go public we do not know.  It might even be as early as today or hopefully, before the end of the month.

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I have been checking Microsoft's Media Creation Tool page.

Still has the 1709 Fall Creator version.

I want to do a clean install.

The version I got is the "Insiders" release.  It may be what is issued (who knows when) as they apparently did some major fixes since it was a new version, not just a KB "patch".

Windows 10 Spring Creators Update Version 1803? In this new update, I like on the start menu. the Start menu includes Reveal highlight, which is an interactive visualization that brings illumination to display hidden borders, helps you navigate, and interact with an app. You’ll see this feature while hovering items in the “All apps” list and Live Tiles.

Additionally, right-clicking a Microsoft Store app, and selecting More, you’ll now see a Settings option that will take you straight to settings page for that particular app.

In addition, the “Documents” and “Pictures” buttons will now appear pinned in the left rail by default.

I have a Inspirion 5448 on 1709 still it seems haven't gotten the update yet

1803 has been delayed.  No official release date, yet.