4 weeks 1 day pregnant

I'm so so happy! I'm about to be 22 and the last time I got pregnant, I miscarried at 13 weeks due to trisomy 13/18. My blood test came back high risk, there was a 1 in 5 chance my baby had it & that's the chances for a 40 year old woman. Somebody twice my age! I am so scared it's going to happen again. Any genetic disorder or defect. I don't go to the doctor until the beginning of May, but I'm going to be so nervous until then. I'm going to be so nervous this whole pregnancy!