Pregnancy symptoms gone at 9 weeks??

I have had nausea every morning from week 5-8. Last week I was so sick I had to leave work. I also had a strong aversion towards anything vegetables or anything healthy. Then all the sudden this week (9weeks) I'm totally feeling normal again. I am still really tired and get some headaches. Breast are not too sore. I can eat salads again. I've had some stomach cramping but not like menstrual cramps. I'm really nervous of having a miscarriage. This is my first pregnancy and I don't know what to expect. I have my first prenatal visit in 4 days. Should I be concerned?