Cover screw visible after two weeks. Advice?

Healing cap or healing screw exposed on the implant is not an issue. It is not like an exposed wound or anything. Depending what your dentist wanted the healing screw to do, sometimes the gum tissue will grow over, sometimes it won’t. It’s only been two weeks so your gum tissue may still grow over. 

Cover screw if visible is generally not a big concern. You should be able to heal uneventfully during the course of your treatment.

If you had a single implant places what you should be seeing is a healing abutment which helps with tissue formation. Cover Screws are generally only used when an implant is buried for treatment such as all-on-4. If you ever have concern about your treatment it is always recommended to see your treating Doctor. At this stage you should be seen for post-ops to ensure everything is healing properly.