Hi there
I had a bit of a nightmare coming off depo but want to share my success story with you!
Last injection October 2015, therefore wearing off around Jan 2016
First period of sorts, May 2016.
Periods before depo were regular. Periods are depo were all over the shop, mostly short (21 days) but the odd 32 day cycle thrown in, just to mess with my mind! I was getting positive opks some months but not others.
We TTC actively between May 2016 - Jan 2017.
Saw the GP in Aug 2016, 21 day bloods taken. Progesterone was borderline, unsure if I'd ovulated
GP suggested re-doing bloods on both Day 3 and Day 21. Suddenly, periods went haywire!
October - December 2016, I have a 14 day cycle followed by a 21 day cycle! Very frustrating, didn't know what to do about blood tests.
Went in Jan 2017 for 21 day blood, planning to do Day 3 blood at start of next cycle if possible. Except, next cycle never came 
I went into see the GP at the start of Feb 2017 and he said "hold on while I check your records....hmmm, yes, I can't see your 21 day bloods were fine and you've ovulated". I replied "I KNOW!" and slammed my positive pg test on his desk. Very satisfying lol.
I'm now 12 weeks pregnant.
I assumed the "it can take a year for your fertility to come back" was worst case scenario. Apparently it's actually quite common. It appears mins really did take a whole year to wear old. I think my crazy short periods in Oct/Nov 2016 was my body resetting itself after the depo finally worn off.
Funnily enough, the month I got my BFP, I assumed my cycles were mucked up, I didn't really do opks and was more focused on finding out if I was even ovulating. I didn't think I'd get pregnant that month. Also I was very unhappy in my job that year but started a new one in Jan. I'm convinced relaxing about the whole TTC thing and also removing myself from a stressful job helps.
Anyway don't despair yet. You are literally coming up on the 12 months of it coming out of your system. Bloody thing can take ages but that's normal. That doesn't mean you'll have any long term issues though. Hang in there!