When can I take a test?

Hi all, this is probably a dumb question but on Friday (6th) I had unprotected sex with my boyfriend, I was expecting my period on Sat/Sun (7/8th) but I have not yet got it (Tuesday 10th). When would I be able to take a test because I’m not sure how long it would take to show a result considering the sex was immediately before my period?

ALSO:

I am on the pill but kind of lazy with it (forget pills and take them at different times so I’m probably not protected by it but it keeps my period VERY regular) and also on the Saturday (7th) I took the morning after pill. I have taken the morning after pill before and it DIDNT affect my cycle so I don’t know if that would be what is making my period late.

Thankyou :)