HELP Implantation bleeding or should I see a doc!?

Yesterday was my last fertile day. My period is not due for 12 days. Two days ago I thought I saw some pink ONLY WHEN I WIPED by it was so faint I didn't think anymore about it. Then yesterday I got a mild cramp on one side and when i stood up I felt a little something come out. When I wiped i was a definitely spotting pink but it was very light. As the day went on it slowly turned brownish and today it is more heavy but I'm still not have to use a pantie liner. Yes I KNOW THIS COULD BE OVULATION SPOTTING  but I have never experienced this in my life and didn't know it existed until I started looking up the possibilities. Me and my boyfriend are TTC but while surfing the web I got a little worried because so many articles say it could be more negative and seriouse than implantation bleeding. Thoughts?