Need some positive vibes

I don't want to be disrespectful at all, but it seems like on almost every post I read here people are talking about all the miscarriages they've had like it's super common...
My heart breaks for those who have gone through it and I'm cheering for you to have your baby this time... But now you've got me terrified every single minute that I'm doomed to lose this baby because it's my first! 
I know it's a waiting game, I know it's nothing that can be controlled... But everything I read said that only 20% of women will have a miscarriage and that if your hcg levels come back early and they're doubling nicely your chances drop dramatically, then drop even more after you hear the heartbeat.
Is this right? I haven't had any signs of a miscarriage at all but you all have me petrified that it's an inevitability :(