I started my period august 7. Took clomid days 5-9 which started on August 11-15. My period was due September 4th and it didn't show up. September 8th I took a blood test and it came back negative. Has anyone every experienced this before? My periods before taking clomid were every 28 days on the dot. I am now 12 days late and took a blood test and full panel yesterday. I haven't gotten the results yet. I'm kinda starting to panic.