LetsGoToUS

https://travel.state.gov/content/dam/visas/policy_updates/CDC_Revisions_to_Visa_Medical_Examinations%20(02-2015).pdf
.... Effective March 1, 2015, all components of the medical examination for visa applicants will be valid for either six months or three months, based on the tuberculosis evaluation....
https://travel.state.gov/content/visas/en/immigrate/immigrant-process/interview/after.html
.....You must arrive and apply for admission in the United States no later than the visa expiration date printed on your visa. An immigrant visa is usually valid for up to six months from the date of issuance unless your medical examination expires sooner, which may make your visa valid for less than six months.......

Hi there!!
Every case is different and nobody can predict how long AP will be. they are conducting background checks and it depends a lot where you were born or professional field. I'm the oldest member of this group. so far I've seen a lot of cases in AP. My husband has been waiting for 9 months. even though all his records are clean and he's a Canadian citizen but was born in Cuba. If you read other post about AP you will see some are done in a couple of weeks, others in months, a few in years. You can request your passport at any time by sending an email to the consulate. They will request it back when they finish with AP. Wish you a very short time of waiting. All the best Idy