Clearblue Digital indicates 2-3 weeks after conception. Not 2-3 weeks pregnant. When you use that kit, you have to plus 4 weeks which makes you roughly about 6-7 weeks pregnant. But it is not always accurate. EDD always follows based on our 1st/2nd scan when gynae can measure the size of your gestational sac/fetal pole. So answer is very simple - you don't know how many weeks you are now until you do an ultrasound. AND not everyone experience pregnancy symptoms. Some don't some will experience it later. Best if you Google yourself. You will find many answers there. Everyone's advice here of course defers according to their experience(s).
each pregnancy varies. i did not experience any nausea or vomitting
It depends. It might be come later or otherwise. Depend on your body