This code will work but it will not contain the current date if it's bigger than 28, if you don't require to save the date this will work for you.
DateTimePicker1.Format = DateTimePickerFormat.Custom
DateTimePicker1.CustomFormat = "MMMM yyyy"
DateTimePicker1.ShowUpDown = True
Dim getdate As String = My.Computer.Clock.LocalTime.Date.Day
If getdate > 28 Then
DateTimePicker1.Value = DateTimePicker1.Value.AddDays(-3)
End If