I would start proviron from week 1 instead. Since you are going to front load the test, your blood test concertration will be very high from the start. The aromatisation of exo test will start immediately. It may take a couple of weeks to notice estrogen related side effects, but its doen’t mean your estrogen is not highly elevated since the start.
If proviron is not too expensive, you can stock up a bit more. 25mg of proviron ED may not be enough for AI purpose.
You know everyone react differently. some get gyno with 250mg test per week, some get hairloss with 25mg of proviron per day.
I like to finish off the cycle with a aromatising androgen, e.g dbol 20-30mg per day for week 7-8, I like to finish strong, and its better on the joints. Why don’t you run 10mg of novla AND 25-50 mg of proviron per day during week 1-8, that should minimise the risk of any estrogen related issues.