BBT help please?

Christi

First cycle charting, first cycle 50mg clomid 3-7. Temp spike at cd9 discarded because I woke up way late. I had my ovulation dip at cd12, and ovulation confirmed cd12 by ultrasound. Is the second dip at 4dpo the secondary estrogen surge? I know it's too early for implantation. Temps are taken at the same time every morning with the exception of cd9. I set an alarm. Just wanted some opinions. TIA :)