If u are due end of February many end January towards begining February ...mines was when I turn exact 35 weeks and I will be 39 tomorrow so about a month and I feel like it was long time ago but yea its up to you ...my recomendations would be end of January :)
Dec is a hectic month for ppl. I always do mine a few months early though. Only because my first I had my shower Feb 18 and had him Feb 21st I had no time to set up his stuff and feel prepared. It's better to do it earlier. Exspecially being on your 4th I'm pregnant with my 4th as well and I know how busy you are just cooking cleaning and taking care of 3 kids lol.
Some people do it the month before, but some do it two months before too. It really doesn't matter. I would do it in January though because December is a hectic month. That's what I did with my oldest because she was born in February.