1 day late

[Mummyto4beautys]

I'm one day late according to my app, last month my af came on the day it should of for 4 days then a week later for seven days I did have a punch biopsy on my cervix on 26th January tho so that might of been why. Took a test this morning and I believe these are negative?

I can't see a line either.
It's totally normal that cycles aren't the same length each time. A day or two later is still considered a regular cycle. Maybe you would like to start tracking your ovulation, that's kinda the only reliable way to see if you are really late or not, as the luteal phase - the phase after ovulation - is normally always the same length, while the first phase can vary.