I had great experiences. I've had multiple nexplanons. Getting it removed is the worst part. I didn't have a period and didn't experience any abnormal weight gain. The no weight gain was huge because I have PCOS.
So far I've had it for 6 months. First 2ish months I bled like crazy, but now I haven't had a period at all. Right after the procedure it hurt a lot and a few weeks after it itched like crazy, but now that's gone.
Haven't gained any weight(not that I know of 😂 haven't weighed myself in 2 months, but I feel I have so I will find out soon) and that's pretty much it.
Take Tylenol once you feel the numbing start to wear off. I have only had good experiences. My only side effects are not getting a period and my arm itches where the implant is like crazy when I get overly hot 😂