Faint bfp for a week can someone shed some light?!

So here goes...I had what I thought was a period on the 10th August then 2 weeks later started with really bad pelvic pain so I went to the doctors and said keep an eye on it and take pain killers. They tested my urine for an infection but all was clear. The next night I started with a brown discharge so the next day I went to work (I work on a maternity unit) and told one of the midwives who also worked on a gynae ward what was going on. She asked if I had took a pregnancy test and said no it hadnt even crossed my mind with just having a period 2 week earlier. So went to get a pregnancy test from the antenatal clinic and there it was a faint positive. She then rang the early pregnancy assessment clinic to see if I could have a scan because the bleeding and pelvic pain could indicate an ectopic pregnancy. I went for an ultrasound but the doctor couldn't find anything in my uterus or in my tubes he checked everything also doing an internal scan. Same again couldn't see anything. They then checked my bloods for the beta hcg hormone and rang me that night with the results which said they were 38 (low) I continued to have a brown discharge without any discomfort for the 

following 4 days, getting lighter each day. I have taken a couple of pregnancy tests over the last week still showing a faint positive. The doctor said to take one in 2 weeks and if it's still positive then have another scan if it's negative and the bleeding has stopped then it's likely that I have had an early miscarriage. Has anyone been in this situation and ended up having a successful pregnancy? I just can't wait and can't help taking tests. I also took a clear blue which indicated 1-2 weeks