Your FRER is definitely darker! And I didn't see a 2-3 on a digi until I was a week overdue af so don't worry about that! Most people see a 1-2 at this stage, if they're lucky - some see a 'not pregnant' at 14dpo.
Those Boots own tests are a nightmare imo. When I was getting clear positives on other tests (including ICs which loads of people don't see clear positives on for ages) and barely anything on Boots own (their early tests). But I can see those lines easily.
I know it's hard and I know it's easy for all of us to say keep calm and try not to worry, but please try to do something to take your mind off things. All this stress and worry won't be helping you and you need to concentrate on relaxing and growing a baby. Do whatever helps you, whatever makes you feel good and remember that right now, you have a tiny little one trying to grow in there, which is a little miracle considering you had given up trying! I don't know what the future holds for you, but at this precise moment in time this little one wants to be here.
Can you ask for betas? Fast tracked? If your surgery can't fit you in then you can go to the path lab at your local hospital and they can do it instead. Perhaps seeing what the number is will reassure you. I know you won't be able to get another repeated until Wednesday (unless they're open Sunday?) but even then you'll be able to have a clear idea of what's happening which is a good thing if it reassures you.
I wish I could take your worries away for you
Can I add that Robo is right about stress. It isn't any good for you or the baby. The thing is, stress produces cortisol, which steals progesterone, which you need to make in early pregnancy before the placenta takes over and makes it itself. It's so important to try not to stress out for this reason. I think we all become stressed in early pregnancy but try to relax and take your mind off everything. Right now you're pregnant and this should be celebrated and a happy time. I know it's hard especially when you have experienced losses, but this time there's every chance it's different and will be here to stay