Insight?

So, my periods are very, very regular. I'm always a day early, on time, or one day late. Those are the three days it always comes. It is usually very heavy with severe cramps.

Here's my situation: my boyfriend & i have been trying for about 9 months. Yesterday I started bleeding (spotting?) Dark brown. It is enough I have to wear a pad but it is not heavy or bright red like normal. I have been cramping. It is just sooo out of my normal...not only is it dark brown & light, it is 5-7 days early? Anyone with any experience with this or insight, I would so very much appreciate it. Thank you!