Ultrasound not showing

Sierra

Anyone who went through the same please share your stories. I am 6 weeks pregnant and my uterus is empty. The doctor said that he doesn't see an ectopic too. The HCG levels were on 707 last week. I took another blood tests for HCG level today which will be released next week. I have not spotted or anything. My discharge is clear and white. What could be a reason behind this?