Hallow dear, I have understood your dilemma. Your doctor has given you correct advice. Ultrasonography after a week or so will give you more clear picture. However, you may get your urine pregnancy test. By this time it should be conclusive. Here I would rather worn you about a condition called as ectopic pregnancy. If the endometrium is thickened but the sac is not seen inside the uterine cavity, it could be present outside the uterine cavity- more commonly in tube. The urine pregnancy test shows week positive result. Please request your Obstetrician/ultrasonologist to rule out the possibility of Ectopic pregnancy. I always say, You have to be ectopic minded to suspect an ectopic pregnancy. This condition is an haemorrhagic emergency if the tube ruptures. So always safer to diagnose in time and tackle it. This can be done now a days because of modern technology. I hope, you have got the message.