Bbt temp has plummeted

Hello ladies! Feeling quite positive today all though I gave in and took a test which obviously was negative because I'm only 7dpo! But however, ignoring the test results (as it's indeed way to early) I have had my bbt plummet very high this am :) anyone able to read this chart and tell me if you think it's a good sign? :) baby dust to everyone! X ​