BFP after miscarriage... terrified. Who else has been there?

Natasha
So we've been TTC since Feb 2016. I have PCOS and irregular cycles, so it's not been the easiest journey. I did get pregnant once, but sadly miscarried around 7 weeks. 
I'm now 10dpo, and have just had a BFP on a FRER. I want to be happy, but I'm just so terrified of going through it again. And docs won't investigate possible causes until after 3 miscarriages, so will just have to wait and see. 
Who's been through this? When does the fear end? Has anyone got any success stories of healthy pregnancies after miscarriage to put my mind at ease?