The scale you're using is called the numeric pain rating scale (NPRS). It's a valid way to measure pain and change in pain, especially after treatment.
Patients who improve by two points or more can give the credit to the treatment, the passage of time, or both. A change for the worse by two points or more is a sign that you need to check back in with your nurse or doctor.
It may be you just need a change in medication. Or perhaps you overdid it and are suffering the fallout for a few days. But any worsening of symptoms without an apparent cause is reason enough to go in for a recheck.
Don't throw the scale away. It's a good way to judge what's going on and what to do next.