Since the date of its accession to the EU, Bulgaria has strictly been applying Council Regulation (EC) No 539/2001 of 15 March 2001 listing the third countries whose nationals must be in possession of visas when crossing the external borders. Visitors not staying in a hotel must register at the local police station within 48 hours. Currently Bulgaria issues national visas only. Those visas do not give their holders the right to enter the Schengen area!
If you do not, get in here or to register here on the site.