A 32-yeаr-оld femаle presents tо the emergency depаrtment with acute оnset of lower abdominal pain with associated vaginal bleeding. The patient states her last menstrual period was 6 weeks ago. She took a home pregnancy test that was positive. She has not yet followed up with her OBGYN. Her vital signs are normal and there is no abdominal tenderness. Her pelvic examination showed a closed cervix, mild vaginal bleeding with no abdominal fullness or tenderness. The patient had a transvaginal ultrasound performed and it showed a fetus with a fetal heart rate of 150. What is the correct diagnosis of this patient?