How often should I get morning sickness?

Aubrie
The day I found out I was pregnant I decided to test because I felt incredibly nauseous. I never actually vomited however it was bad enough I was hugging the toilet for a few minures. It has now been 8 days since I tested positive and have not even felt the slightest bit nauseous. I'm really not experiencing symptoms at all. No breast tenderness, no morning sickness. I'm stilltesting positive, but is this normal? Why would I only experience nauseousness one time?