Random Question

I think I am about 2-3 weeks of pregnant. After I discover that I got pregnant by using Clearblue Digital..But I dont vomit or feel nausea at all..Only headache once a while...I mean I dont feel symptoms of being pregnant..I feel like Im not pregnant...Will my nausea and vomit come later or it might dont have? Coz Im fear of vomitting too much.....