At this point, oil analysis is still probably your best course of action. I'd also recommend a filter magnet or magnetic drain plug in the mean time to snatch up any ferrous material that gets loose in the oil. Pull the filter and take a peek as inspired between oil changes. Filters are cheap and swapping out a filter just takes a few minutes and barely any oil.
Note my signature, but I would not be seriously worried about the engine yet. Most people never even get a look at the oil in their cars and most oil changes will have some degree of trace particles.
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I am not an attorney, mechanic, or member of the clergy. Following any advice given in my posts is done at your own peril.
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