How long to get results of the sequential screen?

[Ms. Shortie]

Hi! I have this OB who I don't think is very good. They lost my lab results from my prenatal labs twice and I finally got the results over a month after I had the blood drawn. I got my blood drawn on Friday for my 2nd set of blood for the sequential and was wondering when I should expect to hear from the office. If I wait until my next visit at 20 weeks is that too late in case it is abnormal and I want an amnio?

Thanks!