Period late for a week.?

my gf period has late but she has the signs 13days ago such as sore , white discharge(different than normal) and now(few days ago) she easily get angry n sometimes moody.we had on 28th january which is unprotected(20seconds)and continue with condom.5days after ,she started to have period symptoms untill today but she still haven get a period yet.she just now got abit cramp on her stomach but disappear very fast.her last period was 4th january.she took pregnancy test 2 days ago with 2 different tester which comes out negative. she told me that every time be4 her period, the signs are same like now. so any1 can let me know what happen to her period?pregnant or any other disease?