Recurring dental implant fistulas

On November 2, 2016 an oral surgeon extracted tooth 20 because of a hairline fracture and infection in the root. I was on an antibiotic prior to the extraction. He then placed an implant in the number 19 slot. For the past 3 weeks i have had recurring fistulas at the implant site. I went back to the oral surgeon and had him look at the implant site. He said it looked fine but put me on a weeks worth course of antibiotics. I finished taking my last amoxicillan pill tonight for this round of antibiotics. I again had a fustula tonight that burst. It is red and swollen on the top of the implant. I punctured the fistula with a pin, drained the pus using two q-tips to push what infection i could out. I have gargled with salt water, brushed the site and used an intibacterial oral rinse. My question is, is the infection that was in my extracted tooth at the time of the implant surgery causing my implant site to be infected, or is something more serious going on that my oral surgeon is ignoring? Could my body be rejecting this implant?