12 week chromosomal abnormality test - what's normal!

Hi everyone,

Looking for a bit of reassurance. Am currently 13 weeks pregnant. Had my 12 week ultrasound along with combined blood test to check for chromosomal abnormalities. Results came back as low risk but am still a little concerned about my blood work. My Papp-a was 0.74MoM which I guess is no major concern but beta hcg was 0.33MoM which seems crazily low, i was dated as 11+6 at the ultrasound when I thought I was exactly 12 so no issues there. Nuchal measurement was only 1.2mm.

Risk of trisomy 21 was 1 in 9000 & risk of 13&18 was less than 1 in 20,000 however I've read that a low hcg can be a sign of 13or 18 abnormalities.

Did anyone else have a crazily low (well, seems low to me) hcg & have no problems. Are there any other issues it could cause?

Would be so grateful to hear anyone else's story.

Thanks