I've had the same experience - trace protein (especially in the first morning sample) is relatively common and not overly concerning. When it went up to +1 and was a late morning sample then it was a bit concerning but still nothing being done more than a test more frequently and watch/wait (& take me off NSAIDs entirely and put me on Lisinipril to protect the kidneys). I also had a low GFR of 58-59 a few times in a row as well. This went up to the mid 60's at last testing with the measures taken so far.
It's definitely something to keep an eye on, but I wouldn't be too concerned at this point. Hopefully you'll be able to talk to your doctor about this as well with very specific questions & you can get more specific answers. In general... If the overall kidney functioning is still doing well (as assessed by GFR, BUN, creatinine, etc.) then trace protein is not too concerning.
Hope this helps...