I don't think there's anything that needs doing prior to 10 weeks. I think it might depend on PCT, but I'm sure it's at your first hospital appointment they'll check your immunity to Rubella etc.
I've ended up at hospital prior to 12 weeks, but that was EPAU with complications. Fingers crossed you don't ever have to venture there.
With Clearblue it's more of a conception indicator. It's a bit of a myth that all women ovulate CD14 plus your HCG levels are determined from when implantation took place, which again can vary from person to person. I think the earliest is maybe 6DPO & the latest is 14DPO. So if you tested on what would be CD28 then you might have only just implanted, so the level of HCG in your urine would be lower.
I did it where I felt a bit funny, so fished out a test I had, I got 1-2 weeks, then tested again and got 2-3, finally got 3+ which is amazing and so relieved.
There's websites that compare beta HCG's which is from a blood test, again such results can vary quite a bit.
I'm so full of useless info from having had fertility tx.