Pee or amniotic fluid??

I'm going to call my on call nurse later this morning but just to hear of anyone else maybe having the same thing I figured I'd ask. About 3 or 4 days ago now I started noticing every time I stood up I'd leak a little. I thought that the baby must be pushing on my bladder causing this. Well here we are days later and it's still happening to the point where I end up having to change underwear a couple times a day. I didn't start getting concerned until it's been getting worse with sharp stabbing pains in my vagina and I kept having cramping last night. I don't wanna panic and run to l&d but it's starting to get to me that this might be amniotic fluid and she might be ready to come. Anyone else?