Period 9 days late / need advice

Im 22 and normally my period is always on time and I use this app to track it, it's now 9 days late with no sign of showing.

I have had unprotected sex with my partner when I was on my 7 day break from the pill and that was 2 weeks ago (I know that's silly but it's done now) I recently started taking the pill again, still no period.

I took a pregnancy test 4 days ago and it was negative, then I took one 2 days ago and still negative, I've now missed a full cycle and have no idea what is happening, is it the pill? Could I possibly be pregnant but it's too early to tell? Is it stress? I'm worried and just want answers has this happened to any of you?

I read online that I should take another test 2 days after my expected period and that's tomorrow so I'll update then!