How common are false pregnancies and miscarriages early on?

napqueen • 30 year old pregnant with my rainbow child. First time mommy. So excited. 💜 Not very experienced on this app, so please be kind.

Clearly I worded this wrongly. I see the tests are positive which I would assume means pregnant right? Well, there is such thing as false positives. I was just wondering how many other women found out 3 days before scheduled period, and had a full term healthy pregnancy? I feel like I’m too early for it to be real.