sharp pain that takes my breath away

I've been experiencing sharp pain all day. It started in my back then my upper abdomen and now it's in my lower abdomen. The pain comes and goes so it isn't consistent but the pain lasts for about 30 seconds to an hour. I've had a baby before so I don't think this is a sign of labor but still a little worried. Anyone experience this? I've had plenty of fluids, food and I haven't done any kind of strenuous activity. I called on call ob and they told me that since the symptoms are so vague that he couldn't say what to do for sure. Just if I continued feeling unwell to go to labor and delivery. I really just don't want to spend 4 hours in the hospital over nothing.