Two week wait!

Bri
I had CD 21 Bloodwork, which said I didn't ovulate. However, thought I ovulated between CD 18-20. Yesterday and today, CD 26 and 27, I have been cramping and a little brown spotting. Could the Bloodwork have been wrong? When should I take a HPT? Has this happened to anyone else? If it's not related to pregnancy, what could it be?