My gf also took 2 preg test on expected day of period and negative and one 3 days after was negative. enough info to say she's not pregnant ?

One week: Urine pregnancy tests need to be done at least a week apart. After a woman conceived, it takes at least a week for the pregnancy hormone to be detectable in urine; therefore, if a test is negative today, and it is not known, when unprotected intercourse happened before the test, a second test in another week would be the deciding test.