Is it normal to have not many pregnancy symptoms at week 5? when do they usually kick in?

Yes, 5 weeks is early though many women do already have some symptoms. Breast tenderness, fatigue, and nausea are most common, in that order. However there is tremendous variability, with some women having no symptoms to others requiring hospitalization. The degree of symptoms can also vary from pregnancy to pregnancy though that tends to be more consistent. Give yourself more time.