It was awesome bc I knew I was never pregnant. It was not awesome, bc how I knew was due to blood spotting every day. Basically permanent period sex and all my undies were stained (bc it was always like barely enough to come past the lips between pees and you weren't gonna catch my ass buying liners 25/8)
Nexplanon releases a constant dosage (micrograms each day) of a synthetic progesterone into your system to mimic your luteal phase (yes, luteal, not pregnancy). At this hormonal level, your body cannot ovulate, cervical mucus is thickened, and your endometrium does not significantly thicken. That means there’s no egg, sperm couldn’t get to it if there was, and it’s safe not to have a period because your endometrium isn’t thick. 99.95% effective with virtually no room for user error for 5 years!
But as for effectiveness I think it's most effective, past tubal ligation and past IUDs. The rate of pregnancy with ligation and IUDs is actually higher than it is with the implant. So if you're using it for period control, DON'T, but if you're using it for pregnancy control, it's amazing except for the small amount of blood thing. But that doesn't happen to everyone