Milanov was born in Bruges, Belgium on 6 July 1991. His father and coach, Emil Milanov, was himself a discus thrower in his native Bulgaria before moving to Belgium in 1989. Philip Milanov won the Belgian junior championship in 2010 with a throw of 54.28 m (1.75 kg), ranking him fourth on the Belgian all-time junior list. In 2011 he represented Belgium at the European Team Championships First League, placing ninth with 54.88 m; at that summer's Belgian championships he was second to Maarten Persoon of the Netherlands but the top Belgian, winning his first national senior title. He repeated as Belgian champion in 2012.