swollen vein

mrs butler
hi everyone,this is my first pregnancy,i thought am 5 weeks but i think am less than that,doctor couldnt see the baby in ultra sound,so i will see her after 2 weeks for another check up!
last night i noticed a swollen vein on my right lower abdomen! it doesnt hurt at all!just makes my back hot!anyone has any idea what it is?HELP!