Hello, and I hope I can help you today. So, if you had a positive pregnancy test and did the test correctly, you should be pregnant. However, if there is no gestational sac visible on the ultrasound there are a few possibilities of what may be going on. First, the pregnancy may just be too small and early to see on an ultrasound. That can be normal if your period is only a week late. Secondly, the pregnancy may not be growing a fetus, which is a kind of a miscarriage (called a chemical pregnancy ) that gives you a positive test without development of a fetus. Most people with this condition will eventually start bleeding and pass the pregnancy. The third possibility, which is the most concerning, is that your pregnancy is located outside of your uterus. This is called an ectopic pregnancy. The most common site for an ectopic pregnancy is in the fallopian tube. The problem with a tubal pregnancy is that, as the fetus grows, the tube is not designed to expand and it actually can burst, resulting in severe internal bleeding and even a risk of death for the mother. Because of this, it is extremely important that you be closely followed by a physician for the early part of your pregnancy. You first need a blood level of your pregnancy hormone taken and then repeated along with another ultrasound in a few days. The hormone level should double every 48 hours in a normal pregnancy, and furthermore, if the hormone level is high and there is no visible intrauterine pregnancy then it is very suspicious for a tubal pregnancy. Signs and symptoms of an ectopic pregnancy include spotting, abdominal pain (especially if it is only on one side), and sometimes right shoulder pain. Dizziness, shortness of breath and fast heartbeat may indicate internal bleeding. If you have any of these symptoms, you should go to an emergency room for evaluation or call an ambulance. So in summary- when you have a positive pregnancy test with an ultrasound that does not show an intrauterine pregnancy, you need to be ruled out for an ectopic pregnancy. A blood pregnancy hormone level (called a bHCG) should be done first, and depending on the result your doctor will be able to determine what is going on with your pregnancy and determine the best course of action. I hope I was able to adequately answer your question today and that this information was helpful. Best wishes for the rest of the pregnancy, Dr. Brown