Creating User twice in sql server for new registration - asp.net

Question

I'm trying to create a new user and everything works fine but it enters the same records twice to my db. I have already tried to kept some breakpoints but couldn't find where am I going wrong.
This is my Registration.aspx code:
Protected Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
Dim msg As MailMessage
Dim UserID As String
Dim ActivationUrl As String = String.Empty
Dim emailId As String = String.Empty
UserID = Guid.NewGuid.ToString
'Create ConnectionString and Inser Statement
Dim connectionString As String = ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString
Dim insertSql As String = "INSERT INTO Users (UserID,UserName,Password,Email,Mobile,Address,CreatedDate)" & " values (#UserID,#UserName,#Password,#Email,#Mobile,#Address,#CreatedDate)"
'Create SQL connection
Dim con As New SqlConnection(connectionString)
'Create SQL Command And Sql Parameters
Dim cmd As New SqlCommand(insertSql, con)
Dim usernumber As New SqlParameter()
usernumber.ParameterName = "#UserID"
usernumber.Value = UserID
cmd.Parameters.Add(usernumber)
Dim username As New SqlParameter()
username.ParameterName = "#Username"
username.Value = txtUserName.Text.ToString()
cmd.Parameters.Add(username)
Dim password As New SqlParameter()
password.ParameterName = "#Password"
password.Value = txtPassword.Text.ToString()
cmd.Parameters.Add(password)
Dim email As New SqlParameter()
email.ParameterName = "#Email"
email.Value = txtEmail.Text.ToString()
cmd.Parameters.Add(email)
Dim mobile As New SqlParameter()
mobile.ParameterName = "#Mobile"
mobile.Value = txtMobile.Text.ToString()
cmd.Parameters.Add(mobile)
Dim address As New SqlParameter()
address.ParameterName = "#Address"
address.Value = txtAddress.Text.ToString()
cmd.Parameters.Add(address)
Dim createddate As New SqlParameter()
createddate.ParameterName = "#CreatedDate"
createddate.Value = Date.Now.ToString("MM/dd/yyyy hh:mm:ss tt")
cmd.Parameters.Add(createddate)
Try
con.Open()
cmd.ExecuteNonQuery()
lblMsg.Text = "User Registration successful"
Catch ex As SqlException
Dim errorMessage As String = "Error in registering user"
errorMessage += ex.Message
Throw New Exception(errorMessage)
Finally
con.Close()
End Try
Try
'Sending activation link in the email
msg = New MailMessage()
Dim smtp As New SmtpClient()
emailId = txtEmail.Text.Trim()
'sender email address
msg.From = New MailAddress("voletykiran#gmail.com")
'Receiver email address
msg.[To].Add(emailId)
msg.Subject = "Confirmation email for account activation"
'For testing replace the local host path with your lost host path and while making online replace with your website domain name
ActivationUrl = Server.HtmlEncode("http://localhost:8769/UserRegistration/ActivateAccount.aspx?UserID=" & FetchUserId(emailId) & "&Email=" & emailId)
msg.Body = "Hi " & txtUserName.Text.Trim() & "!" & vbLf & "Thanks for showing interest and registring in <a href='http://www.webcodeexpert.com'> webcodeexpert.com<a> " & " Please <a href='" & ActivationUrl & "'>click here to activate</a> your account and enjoy our services. " & vbLf & "Thanks!"
msg.IsBodyHtml = True
smtp.Credentials = New NetworkCredential("voletykiran#gmail.com", "india#1a")
smtp.Port = 587
smtp.Host = "smtp.gmail.com"
smtp.EnableSsl = True
smtp.Send(msg)
ScriptManager.RegisterStartupScript(Me, Me.[GetType](), "Message", "alert('Confirmation Link to activate account has been sent to your email address');", True)
Catch ex As Exception
ScriptManager.RegisterStartupScript(Me, Me.[GetType](), "Message", "alert('Error occured : " & ex.Message.ToString() & "');", True)
Return
Finally
ActivationUrl = String.Empty
emailId = String.Empty
con.Close()
End Try
End Sub
Private Function FetchUserId(emailId As String) As String
Dim cmd As New SqlCommand()
cmd = New SqlCommand("SELECT UserID FROM users WHERE Email=#Email", con)
cmd.Parameters.AddWithValue("#Email", emailId)
If con.State = ConnectionState.Closed Then
con.Open()
End If
Dim UserID As String = Convert.ToString(cmd.ExecuteScalar())
con.Close()
cmd.Dispose()
Return UserID
End Function
Private Sub clear_controls()
txtUserName.Text = String.Empty
txtPassword.Text = String.Empty
txtConfirmPassword.Text = String.Empty
txtEmail.Text = String.Empty
txtMobile.Text = String.Empty
txtAddress.Text = String.Empty
txtUserName.Focus()
End Sub
Can anyone say me where am I misleading?