Labor

So my last two pregnancies I was induced so going into labor or Braxton Hicks I never experienced. This one I’m trying to not be induced and these last two days I’ve been having severe back ache and my stomach gets really hard and cramping and it shoots a sharp pain into my vagina. Can that be Braxton Hicks? We thought I was 27 weeks but the dr measured me this past Friday and is saying I’m measuring at least 30 weeks but she can’t get me in for a sonogram until Jan 10 to know for sure. So I’m not sure if it can be like real labor or false.