Bfn-What’s going on?

🌻🌈❤️

I’m currently on CD 27 (12dpo), I usually have a very regular cycle of 24-25 days. I took an IC yesterday and saw a FL but wasn’t convinced so took a frer and (as expected) is BFN. I’ve attached a picture of the test and will post my chart in the comments. I’ve never been in this situation before. The only time af has been late was due to pregnancy. What do I do now?