I tested, got a positive, had a blood test to confirm then tested about a few times after.
I used Clearblue and my first showed 2-3 so I wanted to see a 3+, so I knew that things were progressing and my hcg was increasing as it should.
It's a double edged sword because if you don't get the progression you want, you're worried. If you do, it's wonderful.
I can see why partners think it's a waste of time and money (similar to early reassurance scans) but anxiety in pregnancy is very real and can be so debilitating.
I can only speak for myself but having had the early scan, I can now spend my time looking at prams and changing stations instead of googling MC and ectopic pregnancies.
If it feels right to keep testing, do it.