First Trimester Blood Screening

Hi, I had given my first six tubes of blood two weeks ago. I was never told what they were checking for exactly. I haven't heard anything back from them, but does anyone know what they would have looked for? If I had an std or something was wrong, would they call and let me know? Or have me wait the four weeks till my next appointment to update me on this? Thank you for any info, I'm just really worried.