A little back information:
Fertile days: 3rd to 9th July
Sex: 11th July (penetrated but didn't ejaculate inside).
Period due 22nd July but did not arrive. FRER test both negative on day 4 and 7.
Clear blue tests on day 13 and 14, both negative (digital showed as "not pregnant").
Most recent FRER pregnancy test taken today at day 44.
What could it be? Has anyone else been this late for their period?