I'm more inclined to think it is your first hunch...you are doing more and your body is still not up to speed.
My laparotomy was January 16, a mere 10 days after yours. I vaccuumed carpets for the first time early last week and had pains beginning a few hours after that. All is normal and I'm pain free again. Of course, I haven't vaccuumed, either. Back to my Swiffer duster for the hard floors. The carpets will have to wait.
This recovery thing is new to me, too, and I don't know for sure how long it takes to not feel the side effects of doing more physical things than we did during the weeks we were healing. As I typed this sentence, I felt a little pain twinge in my scar area! And I'm not even moving!
Some have told me 6 months to heal fully, but it really varies by the person and the amount of work done to us.
~Thanks for your reply, yes I think you are right because come to think of it, I recently started horseriding again and also last week I helped the groom at my stables to move about 24 sacks of horse feed at 20 kilos each - maybe that wasn't the best idea......