This is a great question, and there are a few ways you can tell that you are making progress with your healing process.
You will feel your pain decrease gradually over time as you heal, and it should become easier to move around over time as well. Everyone is different, but many people feel a definite decrease in pain and more ease of movement around the third week of using the BFST 3-4x daily, if not sooner. If you have an older or more severe injury, it may take some additional time to feel these results. The more consistent you are with using the BFST 3-4x daily, the better your results will be.
There's another way you can tell that you are making healing progress. When you begin your treatments, you should use the BFST on level 1. As your treatments go on, you will notice that you feel less and less heat over time. That decrease in warmth is felt in response to your circulation increasing, which means that you are making healing progress. When the warmth has faded almost entirely and is barely there for an entire 20 minute treatment, that's how you know that your circulation has improved enough to move up to level 2.