I'm not sure where to put this under

I am 18 and I'm just now getting on birth control. I made the decision to get the implant, anything I should know more about it before I'm set and solid on it? Anything about weight gain/loss?, Acne?, periods? I had only asked about it effecting muscle growth because I weight lift but it doesn't so that's all I got out of it but my doctor told me it was the best birth control out of all the others that are out there.