Negative Blood and HP Tests but way late?

Hi all! I'm feeling incredibly frustrated these days. I'm day 44 on a usual 30-32 day cycle. I had a blood test 4 days ago and it was negative as were previous hpt's. I took another hpt today and it was negative. I had mild brown spotting for a few hours earlier this week and mild cramping sporadically so I've been expecting AF any day but still no dice. Has anyone had anything like this? Any suggestions?