12dpo...bfn...Has anyone gotten a bfn and then a positive after 12 dpo?

15th month trying for #2...I have PCOS and was put on 50 mg of clomid for days 3-7.

I got a peak opk on Cd 14 and Bd cd 14, 16 & 18.

Took a test just now and it’s a BFN😭

Has anyone tested at 12 dpo and got a negative and then tested again and got a bfp?

I’ve been feeling off the last 2 days, here’s what Ive been feeling:

•Go from either being constipated or having loose stools.

•Very crampy

•Abdomen feels kinda full

•Getting car sick (I never get sick in the car).

Do you think there’s still a chance?