so confused about my HCG/ovulation/and first negative HPT

Jenna • baby boy due March 2019 🧡
Ugh I'm so frustrated. 
I am three weeks post MC and I believe I finally got my negative pregnancy test. I go tomorrow for blood work to confirm that my HCG is zero (last week it was 17.5) but I'm super confused because I took an ovulation test just for the heck of it right after I got my negative test and it's saying that I'm ovulating. I don't know if this is a true reading or if it's still picking up some HCG. But on the other hand if I'm ovulating I don't want to miss it. And I'm not able to BD because hubby is away at work so I'm super stressed and don't really know what's going on 😔