What Test Is To Be Taken To Confirm Pregnancy?

hi Dr., heres the problem long story short, my ex girlfriend that i had sex with once 2 moths ago missed both her recent periods she gets her period around the 11th of each month and usually ends the 17th of each month she says, she took 2 pregnancy test 2 days from today (1-20-15) the first one was in mid day and when i asked her if she took it she said i was a dad i cried(I'm 17 years of age) she's 17 as well i prayed and prayed before she took her second home pregnancy test and it came back negative she went to draw blood and urine at her doctors and i looked up that they usually tell the person immediately if there pregnant on the spot, when i asked her she said her doctor has to wait a week at most for her results to come in, I'm scared she might already know she's pregnant and is holding it off trying to find a way to break it to me or she really has to wait all my friends are saying that I'm fine because her second pregnancy test is fresh pee so its more likely she's not but i found out that there are a lot of false negatives and uncommon false positives i need help idk what to consider please someone get back to me.