perios not due til next week and had spotting one day last w

I'm 25 years old and have never had spotting in my life, I went off my BC pill a year ago and me and my boyfriend are trying to have a baby. My periods are usually anywhere from 30 to 35 days since I went off the pill. This month I had bleeding just when I wiped on day 20, 25 and day 26 of my cycle. I am starting to get worried as I have never had spotting before ever. I believe that as my period isn't due for at least another week that a pregnancy test would not work yet. What could be causing this?