It is possible for an ectopic pregnancy to occur when there is nothing visible in the uterus on an ultrasound, especially if you have a right ovarian cyst. An ectopic pregnancy happens when the fertilized egg implants outside of the uterus, most commonly in the fallopian tube. However, it's important to note that not all cases of empty uterus with an ovarian cyst indicate an ectopic pregnancy. Other factors such as timing of the ultrasound and quality of equipment used can also affect visibility. If you suspect you may have an ectopic pregnancy or are experiencing symptoms such as abdominal pain or vaginal bleeding, it is crucial to seek immediate medical attention. Your healthcare provider will perform further tests and examinations to determine the cause of your symptoms and provide appropriate treatment if necessary.