Sudden sharp pain, upper abdomen

Just started happening a few times the past couple days and each time the pain is brief but sudden and sharp, kind of like a tearing or stabbing sensation, and it's around the top of my belly button. Any ideas what might be causing it? I'm used to gas pains and normal cramping-- doesn't feel like either of those. And I've been feeling baby move for a while now too, it's never hurt.