DD and I have flown several times, sometimes just us and sometimes with DH too. If you can, check in at the gate early to see if they have an empty seat they can seat you next to -- not to hide but so you just have more room, as a pp said. The ONLY time I didn't have an empty seat next to me (even if the airline people had to move several others to accommodate me!!) my then-4.5 month old dd kept kicking the lady next to us, who said don't worry about it, she nursed her 4 kids and loved it and completely understood.
We've flown US Airways, Air Canada, and Westjet. I got different 'rules' on each one. So play dumb and do what you want until someone tells you differently about what you 'can' and 'can't' do with your baby on take-off and landing. One flight attendant told me nursing was best and to go for it -- another told me it wasn't permitted and I had to hold her upright. They ALL said though not to strap her into the seatbelt, and that I couldn't have her in my front carrier or sling. Oh well.
I also didn't use the tiny little slab they call a change table in the bathroom, and used the convenient empty seat next to me to change her. I would rather apologize afterwards than ask and be told no. I doubt anyone even noticed (mind you they were all just pee, no smelly poo to give us away

...and I imagine the 'peeing-with-Ergo' manoeuvre is quite similar in style and function to the 'peeing-with-Beco' menoeuvre that I have mastered!

Good luck! Oh one more thing - try to keep whatever you're using for a carry-on/diaper bag small enough to fit under the seat in front of you so you don't have to try to struggle with getting anything from the overhead bins.