At 20 weeks, we will be going for detailed scan. Is it possible for us to not know the gender during the scan?

i just done my 20week scan last week on 27 dec. we couldnt see the baby gender as my baby was on his/her sides and his other leg is blocking the way. so my doctor advice us that the gender will be reveal on next visit which will be on my 27th week. so my point here is.. maybe before going try talking to ur baby so he/she opens up😂😂😂😂