Crazy 2nd period? Implantation?

Sharee • Loving life with my sweet rainbow baby! 💗Amelia Nicole💗
I had a D&C on 9/16. On 10/18 I started my period and it lasted about 6 days. On the last day of my period I had blood work done and my HCG levels came back at 26. *My Dr. Did confirm that was my period* 2 weeks ago I started taking OPK's and finally got a positive and I was also charting my bbt and it stayed elevated after ovulation up until yesterday where it had a large drop but it went back up today, so I'm thinking "yay for implantation?!" 
Ok here's what is confusing...last Friday I had more blood work done and my levels were at 5. Today I went to the bathroom and noticed brown spotting, so I thought "well here comes damn af" because I had been cramping and Glow predicted it for today. Well all that passed was a little bit of brown discharge and what looks to be tissue! Now I have NO af symptoms at all and I'm not bleeding anymore. What the heck just happened?! Was that the last bit of tissue holding Hcg in my system? Am I out for this month?