Is my wife complaining or am I just hearing things wrong?

As a married couple of 30 years I'm genuinely grateful for the marriage we have. If this is the extent of our disagreements then I think we're doing pretty good. That being said we just had a disagreement that I'll put out there. It seems to me that my wife complains about little things pretty regularly and they add up and cause me stress. One of those instances arose today. It's my day off and we've done absolutely nothing. It's been great. She said, "it seems to me that when you were working out of town that you do more on your days off than when you're with me (something that I have demonstrated is not the case). Why is that? By the way it's fine today because I would have chosen to stay home anyway". I just sighed. It's something I do when I stress. She asked what's wrong. I told her that it seems that she's often taking issue with, or complaining about things like this. She disagreed and said that she wasn't complaining at all. She was just curious as to why that was. I, personally, have a hard time hearing it as being anything other than some kind of complaint. So here's the question. Would you say that she was complaining or am I just wound up a bit too tight and I just need to relax? (Internalizing things too much).