Help?

This was my first cycle using preseed, I'm normally very regular and I have about a 28-30 day cycle. Today is my 40th day this cycle and I'm 10 days late for my AF and I'm 25dpo. For about 2 weeks now been having loads of bfns😞 I was wondering if anybody else had anything like this using preseed or if it's not because preseed, even when you haven't used preseed and what was the outcome? Thank you in advance x