Spotting 7dpo

Kelly • Me: 26 DH:35 TTC#1 since Feb 2014
Hi! I have very regular 28days cycles and I usually spot 1 day before AF comes and then it gets heavier the next day. This month I got some spotting 7dpo, only on TP. It has never happened this earlier, still 7 days till AF. I noticed it a few times when I wiped that day and It continued on and off the next day. But it stopped today 9dpo. I haven't had any other symptoms so far. Could I have been pregnant and had a miscarriage? Or could it be IB? What are your thoughts?