Could it have been my period?

So about 2 weeks ago I had some super light spotting, it was brown for the first to days and than was super light pink for the next two, then stopped. This spotting was so light that neither a pad, or tampon was really required.

I had my son a year and a half ago, and my periods changed. They used to be 7 days long and the flow was so heavy. Now they last 5 days, and are lighter than they used to be, but still sorta heavy. I used to have HORRIBLE cramps, but now, I barely even feel them.

So my question is, could the spotting have been my period? I took a test the day of my expected period, and it was negative. I plan on taking another one tomorrow morning, just to confirm the results, and it will be a week after my expected period.

If the spotting was my period, should I be concerned? Thank you so much if you made it this far.