Incomplete Miscarriage? Infection??

[Zoeallisonn]

Hi, I'm new to posting on this site, but I've read through several threads to try and find answers on my situation and have come up empty handed. I'd really appreciate some help. I'm 18 and for the past 3 months have been having severe abdominal pain. In early September, I finally went to the doctor where they did an ultrasound revealing an early pregnancy. However, my urine and blood tests both came back negative. 2 weeks later, my period started and it was the worst I'd ever had. I was cramping really bad and bled through tampons instantly. My August period had been similar before I'd even known about the possible pregnancy. My doctor now thinks it could be an incomplete miscarriage that left the sac, but I can't go to an OBGYN for another month to see if I need a D&C. My normal doctor is concerned for infection. I've already had bad back and cramping pains for months and now am experiencing unusual discharge. I'm scared to wait. Has anyone experienced something similar?