ultrasound but no baby

There's a chance you have an ultra late conception. Usually you ovulate at week 2, and conception happens after that. However, there's a chance that your cycle is irregular and you didn't actually ovulate at week 2 but a lot later, and therefore the actual weeks is inaccurate. Normally you will see a sac after week 5-6 of your pregnancy, but not before. If your conception is late, maybe week 6-8. which week did you see the doctor? week 1 being the start of your last menses.