Extremely itchy at night!

Hi I am currently 12+5 weeks pregnant and the last week I have been getting extremely itchy all over my body and it's only at night.  it is increasingly getting worse and I don't see my doctor again for 3 weeks (he is difficult to get an appointment with so a sooner appointment is out of the question) has anyone had this symptom before and has it turned out to be nothing or should I be concerned? I have have had 2 miscarriages and a chemical pregnancy previously which has made me more concerned about this pregnancy then probably necessary so I don't know if I'm over reacting.