I had it twice so 6 years all together, i have just got a new one in after taking a few years off to see what happened, also didnt have a boyfriend
I found i lost weight then it was steady, i put more weight on when i was not on any contraception, also i found you dont get the crazy week, where all your clothes gang up on you, everything is rubbish, and the slightest thing makes you want to cry or shout at people, then feel really bad about it.
had used depo before just didnt like having to remember every 3 months, like the fact that i could just forget about the implant. thou i would say it does take a few months for your periods to settle down, as in bleed for a week, then nothing then a week again that was a bit of a pain, but after that when you dont get your periods for ages, it is the business!
you will notice that your periods start to come back at the begining of the 3rd year you have it in, but i feel best contracptive ever, would defo recommend it, and have done to a few people.