No.
Bulgars were a seminomadic people, probably of Turkic descent
originally from Central Asia, who during the 2nd century migrated
from the Northern portions of Central Asia into the North
Caucasiansteppe. Anthropological data collected from early Bulgar
necropolises from Dobrudja, Crimea and the Ukrainiansteppe shows
that Bulgars were a high-statured Caucasoid people with a small
Mongoloid admixture, and practiced artificial cranial deformation
of the round type. The modern Bulgarians have descended from three
main ethnic groups which mixed in the Balkans during the 6th - 10th
century: local tribes, known as the Thracians; Slavic invaders, who
gave their language to the modern Bulgarians; and the Bulgars, from
whom the ethnonym and the early statehood were inherited.
According to the Gothic theory,Croats would be descendants of
Ostrogoths/eastern Goths. This theory is based on a historic
chronicle from Thomas the Archdeacon called 'Historia Salonitana'
where he mentions Croats as Goths. Also, Slavs in area of today
Croatia are equated to Goths in Chronicle of the Priest of
Duklja.