I worked on most of the bootcamp tests except for PAT and reading a month before my actual test. So this was basically after going through chads videos twice along with his quizzes for the chemistries. As for biology, I started bootcamp right after I finished Feralis.
The PAT and reading I started about 3 weeks before the test. I tried to do a CDP and bootcamp PAT about every day or every other day at least until the real thing.
Whenever, 3.5 weeks is a looooong time away. Seriously, the sooner the better so you can find your weaknesses and give yourself more time to work on them.
Spread them out. Take a test now, and then in a week take another. This way you get to see your progress. Your last week before your test you should only have 1 left in my opinion. If I could do it all again I would leave my last week for all review. So that gives you 2.5 weeks to do 4 tests. Maybe 2 tests a week.