Concerned

Angela
I am now nearly 3 weeks late. My doctor does not believe me and my tests won't show a positive. My mother went 4 1/2 months through a pregnancy without a positive test. My doctor won't do a blood test and won't refer me to an OB/GYN for an exam/ultrasound. I don't know what to do. 
I can not explain it but I know without a doubt that I am pregnant. Any advice would be incredible