BBT Chart

Kerri • Pregnant with #4 after IUI for our twins 7/3/16 and our surprise Singleton 11/16/17
I'm really confused. I think I ovulated at the 2nd spike not the first but not 100% sure only OPK'd until the positive appeared for the first spike that's labeled. My period is do today (or sunday depending on the app) cramping is my only symptom and my nipples are hard but not sore. No bleeding of any kind, bfn on first response 6 days sooner yesterday at 4:15pm. Someone help me with this chart?