@Dandelion89 congratulations! I think that's fairly usual at that stage - I don't think 3 days is a worry. I don't think it's an exact science. I measured 2.5 weeks behind at 8 weeks and despite a heartbeat, that ended in mc the next day. However googling at the time seemed to indicated a few days either way is very usual.
I'm sorry I've missed a few other new people - Welcome and congratulations!
I sent myself crazy with testing - definitely by 6 weeks there was barely any darkening of tests despite examples on the internet. I had to be very firm with myself about stopping! It was very hard.
I'm not sure how best to advise dealing with the early anxiety other than constant mantras "today I'm pregnant" "no news is good news" - I also know of many women who spotted throughout pregnancy, and even had big bleeds. I did feel low and lonely though for a long time. It's literally only been feeling regular kicks that's helped - though I've been worried today as I don't seem to be feeling them as strongly! (I think I had a growth spurt and don't feel it as much then baby grows and a do again.) (I hope)
I'm not sure the worry goes completely- I'm worried about all sort of things; autism, early birth, loss of movement, how my son will cope. I'm 40 so an older mum. I just try really hard to challenge those thoughts as much as I can.
This thread was very helpful in the early days for helping me get through - just posting helps. I googled everything and sort of accepted I was doing it as it didn't make me panic or get really down. If it did I would have avoided it though. Scans do worry me, I get terrible scanxiety, so I didn't have reassurance ones except at my Nipt test, which ended up being at 11 weeks anyway and I had the 12 wk one a week later.