Clear blue digital not matching up-weeks indicator

Hi Ladies

So my last period was on 16th Match and I ovulated around 3rd or 4th April which would put me around

4wks + 3 days.. I did do a clear blue digital a few days ago and said 2-3wks in which I conceived which puts me at 4-5wks pregnant (which is about right)

But due to previous miscarriages and not being able to help myself I thought I’d do another test today and now it says 3+ weeks?

According to the pamphlet it means I conceived 3 + weeks ago which doesn’t make sense

I know they aren’t 100% and I know it doesn’t tell me if it’s viable or not and yes I’m getting blood work done and an ultrasound will be done around 6-7wks to check viability due to multiple miscarriages

Just wondering if anyone else had this also .. maybe means high HCG ?

I got my 1st blood draw and will get results on Monday and I have another two to go after that