If AF is due in 2 days, it's very hard to say, but yes, anything is possible. Remember you need to have a build-up of HCG levels in your blood for a viable pg...
But I am confused, if AF is due in 2 days and you say, there is no sign of her, I don't know what you mean by this?
Do you mean - it dosn't feel as though AF is coming?
Maybe it's just too early.
You need to wait until AF is late by a day or so.
Do a pg test - this should show POSITIVE or NEGATIVE - a small HCG level is enough to show a POSITIVE PG TEST
Good luck with everything!