BFN but pregnant?

Did any of you girls ever get a BFN but still ended up being pregnant?

This morning I took a First Response at cycle day 31 and it was negative, AF due tomorrow as per Glow, but I still feel I may be pregnant, just a gut feeling as my cramps have not been the same as usual. I also started working out this month and I know that can delay your period.

Any thoughts would be much appreciated, thank you 😘