DELAYED PERIOD WITH NEGATIVE PREGNANCY TESTS

I took my depo shot on 19th October thus a day before my fertile window will start.

I was advised not to have unprotected sex for at least 5 days.

But I had sex on the day I took the shot and had unprotected sex on 21st, 22nd & 23rd October (all within my fertile period ).

My period is late (about 28days) with signs of pregnancy but home pregnancy tests come out negative.

Could I be pregnant?