You put in your age and weight and previous births and it calculates your miscarriage risk by day! It seems pretty accurate according to other articles I have read.

I am only 3w6d according to ovulation day and I told my partner last night about my bfp. He refuses to get excited this early because he said miscarriage is really common in early pregnancy.

Started freaking me out and I started googling like crazy. Anyway, I have a 76.8% chance of a successful pregnancy as of today and it will continue rising each day.

The website is

https://datayze.com/miscarriage-reassurer.php