strangest period month

I've been TTC for about 6 months. I'm a very regular person, same time every month. Well, I was supposed to start this month on the 16th (today). On the 11th I started bleeding light, and had a light period for 3-4 days. No cramps at all.  Thought it was very odd for my period to come early but it seemed heavier flow than what I've read would be implantation bleeding. Well, here we are on the 16th after being 2 days completely OFF my period, I had my TYPICAL cramps and began my period today again as I originally had expected. I'm wondering who thinks the first bleed was implantation???? This has never happened in my 10 years of having a period!