Implantation Bleeding

I started spotting brown the night before AF was due and then the next day I had a lot of brown blood similar to my period (enough to need tampons). This lasted 5 days so I was convinced it was my period. As soon as it started to slow down on day 6 where it was just spotting again, I started testing for ovulation. I have a short cycle so it was normal for me to start testing right after my period. It came up positive for ovulation. Then I tested the next day in the morning and in the afternoon and it also came up positive. This made me wonder so I decided to take a pregnancy test. To my shock and delight, it was positive!!! So I went to the nurse to get a formal test the next day and it came up negative. I was so upset! Well, I called the OB nurse and she told me I just came in too early and told me to come back in a week. The next doctor's test a week later came back Positive!