Pregnant sister says I am, I don't think I am.

So my 12 week pregnant sister and I have been talking and I told her about my symptoms. We are basically the same person when it comes to our fertility and cycles. She think I am pregnant. I think it's just my period coming. But my symptoms are:
* very sore boobs ( my favourite sleep position is on my stomach and I can't now) 
* Fatigue (am now sleeping 10+ hours one day then 30mins the next cause boobs hurt) 
* light pink discharge a week ago
* Loss of appetite (usually have a huge appetite)
* nausea 
* general off feeling 
My period doesn't usually give me most of these. I do sometimes get nausea from cramps but I have no cramps this time. Going to doctors Tuesday. Opinions??