What’s going on?

First of all I have a 11 month baby and I am still breastfeeding 4 times a day, recently I have weaned her a bit. I haven’t been cycling since babe was born so imagine my shock when I got a positive hpt at the beginning of Dec. It ended up being a chemical pregnancy December 8. I bled for a few days and then stopped. A couple days ago i had a tiny bit of spotting when I wiped and nothing since. I have had headaches, back aches and bouts of nausea here and there for last week. I did a hpt today and it was negative or vvfl. It’s been almost a month since my CP. Any insight?