Early period only lasted 2/3 days? Help!!

Hi,
​My SO were TTC over the summer...taking a break now. We had unprotected sex 9/5 & 9/6 (highly fertile days according to ClearBlue advanced OPK). I ovulated on 9/10. My cycles are usually 29 days and periods last 5 days. I was due for AF on 9/27 but started 5 days early on 9/22. I had medium/light bleeding 9/22 & 9/23 and spotting on 9/24, now today...nothing! This seems so strange as it never happens to me. Any advice would be greatly appreciated! TIA. :) I should also probably note that I was on implanon from January 11, 2012-July 7, 2014.