Stress can cause AF to be late hun.
An ectopic pregnancy hmmmm try not to jump onto this conclusion Bek

but to answer question at this stage IF that was the situation it may not show on a home pregnancy test yet. We had this ordeal I started with spotting before AF then I had AF then I had spotting proba a week after what I thought was my period I got a positive result but the hormone level on bloods was low and teh hosp tests were neg ... so I guess it depended on brand too in my case but defo wasn't around the day that AF was 'due' that I tested week+ after I would say.
Wishing you luck on your bloods x