What can it be?

Diana

Sorry i don’t know where to post it. I had my baby girl 5 months ago. when she was maybe 3 months when I would lay down I would feel something move inside of me but just laying down. Yesterday I sneezed and I felt my stomach move in a weird way and today the same thing happened. What could it be? I don’t think I’m pregnant I took a pregnancy test last month but I’m waiting for my period it’s due Saturday. Please help