Don't know what was going on

Last month I was late by 3 days this month I was late 6 days then had brownish pink spotting and then the next day was a little more red. My periods are 3 days long and this one lasted 8 days. The last two days were light spotting again. I took two test before I started to spot and it was positive at the beginning and then it faded. I am thinking of calling my doctor to see what is going on. I have had a couple of friends/co workers say that they think I had a miscarriage. But I don't know. What do you think?