Feeling good but...help with last row

So I've finally been able (after several days of searching) to come up with and modify VBA code that will look for "Y" in column Q of three worksheets and copy the entire row to another worksheet ("!!").

My problem is with z = 3000

I'm trying to reduce the amount of processing it takes to find the data I want and make this code the simplest I can.

I've looked and tried several examples but can not get a last row search, instead of specifying the last row as 3000. Eventually I will have to search more than 3000 rows for the information I want.

Any help is appreciated.

My code:

Sub Test()
   Dim i as Integer
   Dim j as Integer
   Dim cal (1 to 3) As String
       cal (1) =  "Incident Data"
       cal (2) = "Change Data"
       cal (3) =  "Task Data"

   Dim x as Integer
   Dim y as Integer
   Dim z as Integer

y = 17
z = 3000

j = 2

For x = 1 to 3
For i = 2 to z

   If Sheets(cal(x)).Cells(i,y) = "Y" Then
        Sheets(cal(x)).Select
        Range (Sheets(cal(x)).Cells(i.1), Sheets(cal(x)).Cells(i,17)).Select
        Selection.Copy
        Application.Goto ActiveWorkbook.Sheets("!!").Cells(j,1)
        ActiveSheet.Paste
Else
    j = j -1
    End If
    j = j +1
Next i
Next x

End Sub