Check if URL has valid page - vb.net

Question

I want to check if URL has valid page (not 404, just 200).
Code I've tried:
Dim request As HttpWebRequest = DirectCast(WebRequest.Create(myurl), HttpWebRequest)
request.KeepAlive = True
Dim response As HttpWebResponse = DirectCast(request.GetResponse(), HttpWebResponse)
If response.StatusCode = HttpStatusCode.OK Then
MsgBox("OK")
End If
Yet every URL that I enter leaves OK response, even if I enter http://mywebsite.com/blahblah.
It's not same on all websites (works fine with example.com), but it doesn't work on my website. Why?
In my browser I see 404 page, but code says it's OK.
Edit: Just to mention that my website has Cloudflare on.

Answer 1

Try this out and see if it work's for you... As mentioned above in my comment's:
A 404 just means the page isn't found on the server, status will return ok even if a page isn't found and the server was reached and responded
Public Class WebPage
Public Property PageSource As String = String.Empty
Public Property Status As HttpStatusCode = HttpStatusCode.NotFound
Public Property WebError As String = String.Empty
End Class
Public Shared Function GetWebPage(ByVal Website As String) As WebPage
Dim web As New WebPage() With {.Status = HttpStatusCode.OK}
Try
Using source As New System.Net.WebClient()
web.PageSource = source.DownloadString(Website)
End Using
Return web
Catch exweb As WebException
If exweb.Status = WebExceptionStatus.ProtocolError AndAlso exweb.Message.Contains("404") Then
web.Status = HttpStatusCode.NotFound
Else
web.Status = HttpStatusCode.BadRequest
End If
web.WebError = exweb.Message
Catch ex As Exception
web.Status = HttpStatusCode.NotFound
web.WebError = ex.Message
End Try
Return web
End Function
Usage Example
Dim webObj As WebPage = GetWebPage("THESITE")
If Not String.IsNullOrEmpty(webObj.WebError) Then
MessageBox.Show(webObj.WebError)
ElseIf webObj.Status = HttpStatusCode.OK Then
MessageBox.Show("OK")
End If

Answer 2

This will do what you want.
Function URLExists(url As String) As Boolean
Dim Request As Object
Dim ff As Integer
Dim rc As Variant
On Error GoTo EndNow
Set Request = CreateObject("WinHttp.WinHttpRequest.5.1")
With Request
.Open "GET", url, False
.send
rc = .StatusText
End With
Set Request = Nothing
If rc = "OK" Then URLExists = True
Exit Function
EndNow:
End Function