symptoms of twins!!

just freaking out a little..... twins run in my family A LOT and my mum keeps telling me she has a feeling I'm carrying twins. (she has them-my brothers). I have my 12 weeks scan on 2nd Jan and nervously awaiting it 😬😬. what symptoms did you have? I have all day sickness that has eased now and only results in bad nausea, Have dizzyness also and I'm showing already. (3rd baby)