I've been taking practice tests for about a month now (only 1 or 2 a week) but every test I've taken my score has gone up. It's making it really challenging to anticipate where I'll be on test day. Any thoughts?

Diagnostic: 156

June 2015 test: 160

Recent practice tests:

Pt 62: 165

Pt 63: 166

Pt 64: 167

Pt 65: 168

Pt 66: 169

My hope is to take PT 67-70 before test day, maybe those will give me a better picture?