VBA Check If A Cell Is Empty - Move 7 Cells Over And Check Again (Loop)

I have data in Row 53 that spans 7 columns, but stays in the same row. I want to design a loop to select every 7th cell in that row and check if it is empty. If not, add onto a "counter" then display the final number of occupied cells (the value of the counter) at the end. This is what I have so far, but I get all sorts of errors.

Code:
Sub Tester()

Dim WB As Workbook
Dim WS As Worksheets
Dim modCounter As Long
Dim Cell As Range

Set WB = Workbook("Transverse Series.xlsm")
Set WS = WB.Sheets(BM18)

[Code] ......