26 weeks i need advice on down syndrome plz

Felicia
So i had the Panorama test. done at 10 weeks came back not enough fetal data in dna so fast forward i didnt take the second part of the test in time frame i needed so ive had 4 ultrasound since then all came back normal so today ob tells me baby has test came back for .downsbut that dont make sense if i drew blood at 10 weeks an test were inconclusive now 26 weeks an all ultrasound were fine how would she know the baby haf downs there noway to tell so now i have to.see a specialist an then she say your baby probably dont have it just to.make sure tho but wouldn't u think they would of known by now ultrasound an everything they did i just dont get it any advice is very appreciated