So i bought my first time the dji mavic pro. and i was watching youtube video it says i need to calibrate the compass everytime i fly? is that true? i didn't calibrate anything yet?

You shouldn't have to calibrate the compass often. See the Mavic Compass Calibration Guide for the best known compass calibration practices.

Hi. Thank you for reaching DJI Forum. It is not required to calibrate the compass every flight that you'll be having. You are only required to do that if you are going to fly in a different location or if the app says so.

DJI Wanda Posted at 2018-9-18 07:30
Hi. Thank you for reaching DJI Forum. It is not required to calibrate the compass every flight that you'll be having. You are only required to do that if you are going to fly in a different location or if the app says so.

I bought the mavic pro lately. So it's still in the box i wanna know when i open the box should i calibrate it as first time?

charbel1011 Posted at 2018-9-18 07:31
I bought the mavic pro lately. So it's still in the box i wanna know when i open the box should i calibrate it as first time?

Yes, you should.

I've posted this before, but will do it again.  I've had my MP for 2 years and haven't calibrated ANYTHING on it yet.  It flies beautifully, has never crashed, and I'm VERY happy with it.  I'll consider calibrating something when it tells me it needs to be done.

charbel1011 Posted at 2018-9-18 07:31
I bought the mavic pro lately. So it's still in the box i wanna know when i open the box should i calibrate it as first time?

Make sure when you do calibrate (as answered ''Yes, you should'' by DJI Wanda); that you calibrate Mavic Pro's compasses well away from any possible source of magnetic interference.
Minimum recommended distance is 10-meters.  Personally, I like being further away - as in undeveloped grass field.

Make sure there are no - overhead or buried power lines, buried metal pipes (water or gas), metal fencing, or metal structures within 10-meters of you.  

Do not perform a compass calibration over a concrete sidewalk, driveway, roadway, parking lot, or dock pier.  Highly likely there is steel in anything made with concrete.
Make sure you are not wearing any ferrous metal or have any kind of magnet on you during compass calibration.
If by chance you have medical implant that is made of ferrous metal, you may want to get a friend to do the Drone Compass calibration Dance.  Make sure to covertly film the friend.

When Mavic Pro's two compasses are correctly calibrated, in same area calibration was done, both should have short ''Green'' bars under Sensor menu for Compass field interference.

I think if you follow msinger’s advice you won’t go far wrong.

My MA makes me calibrate it almost every time I fly, is this abnormal?

I see your link and heres another
https://forum.dji.com/thread-142359-1-1.html