My own advice would be to log this kind of thing, and other occurrences like it, and just do that: maintain journal entries of what you have felt and when and for how long, and what else was happening at the same time, such as sleep patterns, diet, exercise, anything that you think might be relevant.
But I wouldn’t see the doctor (other than for routine checkups) unless I felt pain, loss of range of motion, persistent and unexplained weakness or inability to function in ways that were normal for me, or other “capability” type of issue.
Because the fact is that “numbness” (even “prolonged numbness”) can have so many causes, both benign and potentially life-altering (such as Lupus and Multiple Sclerosis, to name two) ... but it doesn’t mean that just because you feel some numbness that “you must have Lupus” or worse.
What I mean is, if you see the doctor and tell him the generalized complaint that “I’ve had this numbness for a few weeks” (absent pain, absent “range of motion” issues, absent “weakness”, etc.) then he could start to run tests for everything under the sun if he thought you needed that kind of certainty and reassurance (and could cover the costs) ... or he might just suggest the same thing: Let me know when it gets worse.
The problem is that some diseases, and I know that MS is this way, have no “sure diagnosis”. When every other potential cause of symptom (including numbness, but also including a lot more than “just” that) is ruled out, then a doctor might say, “I think you have MS.” Because there’s no way to know for certain. I don’t know if Lupus is like that; the tests for that may be more certain.
But in point of fact, as we age (and especially if we move or sleep in awkward ways sometimes) our joints act weird – even without autoimmune disease as the cause – and nerves get pinched (or twisted or something) and we can feel out of sorts for quite awhile sometimes.
Maybe after reading all this you’re thinking, “Great, I might have Lupus or MS and the advice is ‘do nothing?’ I don’t think so!”
So try this if you feel a need to “do something”: See if you can schedule some physical therapy through your doctor / insurance carrier. It’s relatively inexpensive and can help you feel a lot better. They can do amazing things to correct the kinds of muscle / skeleton issues that might be all you’re experiencing, and if the problem goes away, then so does your worry about “how much worse it could be”. If the problem persists or worsens during PT (or while doing the exercises they’ll suggest at home), then you’ll have a clear indication that something else is wrong, and will have more to discuss with your physician – and a logbook.