16 dpo and lines still really really light.

I keep seeing a lot of posts with ladies posting strong strong lines from 8dpo on. My lines at 16dpo are still as light as they were at 13dpo when I got my first positive. I go in to the Dr tomorrow where if I remember correctly they just do a urine test to confirm pregnancy, not a blood test, I'm worried it's going to be negative. I only have the cheap test strips on hand but am tempted to buy some frer to see if those are any better? Should I just hold off on buying tests, if they are still light it might just make me worry more, Idk what to do. I keep replying to posts similar to this saying stay calm dont worry and now I'm the one freaking out. Ugh!!!!