Pregnancy Test Question, difference between tests..

Raina

So when I first tested on clearance, my line was darker. In the hope of saving some money and to give me some peace of mind to make sure my little bean is still on board (it's my first pregnancy, so I'm a nervous mess lol) I bought tests at the dollar tree. The line on these were still there but not as dark. Is this normal or should I be concerned. Still a bit nauseous but not as much as I have been. I go to Dr for my confirmation appt on Friday.

Thanks in advance ladies!