No point i testing yet, ANother early symptoms person here. I always know (twice anyhow) taht i'm pregnant well before tests are positive
The truth about morning sickness is that no-one really knows what causes it, Hcg is just one theory but doesn't explain everything. Could also be to do with oestrogen, blood sugar and stuff we don't even know about yet
So thats why the tests are negative, but you'll know soon!