The Delete event fires once for each record being deleted.

It would therefore be possible to use a Form level variable to count the
number of records being deleted.

In the General Declarations section of the form (top of the module, with the
Option statements):
   Dim lngDeleteCount As Long

In the form's Delete Event:
   lngDeleteCount = lngDeleteCount + 1

In the form's BeforeDelConfirm:
   MsgBox "Abount to delete " & lngDeleteCount & " record(s)"

In the form's AfterDelConfirm:
   lngDeleteCount = 0

Note that this is for an MDB, not an ADP where the events don't fire in that
order. Also, assumes you have confirmation turned on under:
   Tools | Options | Edit/Find | Confirm.

One option would be use a SELECT query that utilizes the same WHERE
criteria as the DELETE query. If the query is a saved object, you can
execute DCount() on it to get the number of records OR if the WHERE
statement will change periodically, you could use DAO to open the
recordSet, move to the last record and get the value from there.

(Roughly)

strSQL = "SELECT * FROM tblTransports WHERE txtType = 'W';"
set rs = CurrentDb.OpenRecordSet(strSQL, dbOpenForwardOnly)
rs.movelast
Debug.print rs.RecordCount