With my first baby, I didn't have any symptoms until about 8 weeks. My symptoms never got very strong. I never had sore breasts and although I had a little nausea, it was barely noticeable. The pregnancy was fine.
Symptoms, or lack thereof, really have no bearing on whether the pregnancy will be successful. Your nervousness is normal, but (I know easier said than done) don't waste your time worrying about what your symptoms mean.