No embryo

Randi • Mommy to a beautiful little girl and pregnant with baby #2 due august 2015
Had an ultrasound. There is a sac but no baby. I got my blood drawn for levels to be checked and I will go back on Wednesday to redraw and hope the levels double. I also have another ultrasound scheduled in 2 weeks. Anyone else go through this? According to my calculations I should be 6w1d but the sac was measuring between 4-5.