Yes, I am having regular periods every month. I thought I was just ovulating too, but this feeling doesn't only come the wk before, during, or after my cycle. It comes at different times. It came once even while I was grocery shopping and once when I was at work. Afterwards my body was weak and I could barely walk.
I am assuming that you are having regular periods every month. Sometime if this occurs in midcycle around cycle day 14, it means that you are ovulating. This is called mittelschmerz.