I have been nauceous for 4days and gagging when I eat. My expected period date was the 24th of this month. Usually my breast get tender a week before period, but it hasn't.Could I be pregnant?

You could be.

Are you? There's no way for anyone on the internet to tell you. We need one of two things to confirm pregnancy, urine, or blood. We can't get either of them over the internet.

You have access to both, so why not try taking a pregnancy test?