LATE!!!!!!

Oscar • Liked her from the first time I heard her voice. Loved from the first time I saw her. Will never let her go.
My gf is 4 days late on her period and she's taken SIX test already and all are negative. She has been stressed out and she has diarrhea for like a week none stop and today vomiting as started too. Anything she eats doesn't sit well. I've heard all these things are signs of pregnancy. Not sure what I can do to help her not be stressing about situation. Should we keep taking test?