Welcome to healthcare Magic.
I have gone through your query and Would like to reply in detail as follows:
1. The remnants are possibility.
2. Please get repeat ultrasound
I hope your doubt is clarified. Let me know if you wish any other information.
If you wish, you can directly contact me by clicking following link: http://doctor.healthcaremagic.com/Funnel?page=askDoctorDirectly&docId=63059