How possible is the digital pregnancy test?

because i did two and one was in the morning and it came positive ....the next one i did it at night and it came out negative....

Pregnancy tests will not yield an accurate answer until a minimum of 5 days before a missed period. That means that if you have sex and dont expect your period for another 10 days, wait 5 more days (or more) before taking a test. Of course you are anxious to know if you are pregnant, but you will have a much more accurate answer (and save a lot of money on needing to take several tests) if you just wait until the correct time.

PS: this is all included in the instructions of any pregnancy test.

Well how soon are you doing it after intercourse? You should wait a while (I think I heard someone say like two weeks) after intercourse before using a pregnancy test.

get a morning after pill at any drug store in the US.