Best to arrange the first scan at week 8 onwards. Some ladies go earlier and cannot see anything inside the sac, end up worry excessively. At week 7-8 u will be able to see a tiny fetus and heartbeat already. Before that u can go have a urine test at polyclinic to confirm the HCG levels.
In my experience (and gynae confirmed) , cheap preg test kits work the same as the expensive clearblue kits.
I tried different brands of cheap kits, including the type in your pic (each one is like 50c - $1 on average, cos I was in denial over the positive results yet refuse to pay for clearblue), not necessary to buy the expensive ones