Option Compare Database
Option Explicit
Dim IsInserted As Boolean
Public Function mycounter(x)
Dim rst As Recordset
Dim n As Long
Static M As Long
On Error Resume Next
    Set rst = Me.RecordsetClone
    Err.Clear
    rst.Bookmark = Me.Bookmark
    n = rst.AbsolutePosition +  1 
    If Me.NewRecord And (IsInserted) Then
        'Me.NewRecord может быть после удаления записи для всех'
        rst.MoveLast
        n = rst.AbsolutePosition +  1 
        n = n - Me.NewRecord
        M = -IsInserted
    End If
    If Err <>  0  Then
        rst.MoveLast
        n = rst.RecordCount +  1  + M + IsInserted
        M =  0 
        Err.Clear
    End If
    mycounter = n
    IsInserted = False
End Function

Private Sub Form_BeforeInsert(Cancel As Integer)
    IsInserted = True
End Sub

Private Sub Form_Delete(Cancel As Integer)
    'Me.Recalc
    Me.Refresh
End Sub