The conception indicator on these tests works by testing the concentration of HCG in your pee.
I think I read somewhere that your HCG level are supposed to almost double every day after implantation, peaking around weeks 9-12 and then tailing off from week 13 onwards as the pregnancy goes on the placenta takes over more.
So technically in the first trimester the longer you have been pregnant higher the concentration of HCG in your pee. However, the trouble is that the stage of pregnancy is not the only thing that affects the concentration of HCG in your wee. What time you test, how much you have already pee'd and how much you have drunk that day will also affect your levels.
The conception indicator is only a really rough guide - the most important thing is that the test says you are pregnant
PS HCG levels vary loads from person to person and pregnancy to pregnancy too - it might be that compared to the digi-tests average levels they base their conception date estimates on your levels are a little higher. If you have been to the docs today and they seem to think eveything is ok I would just go with the flow for now xx