How does “nexplanon” work

I had Nexplanon in my left arm for 5-6 years straight. I think it’s only “certified” for 3 years but doctors tell you that there’s been studies that say it could last longer. I was just lazy and never had it removed. As far as my period I had a normal period for about a year and some change. Then about 2 or 3 years in I didn’t have a period at all for a whole year and it slowly started coming back. Every three months, then every two months to every month. I know other people who have an Nexplanon and that’s not exactly how it’s worked for them. Some people had their period the whole experience. Some people didn’t have a period for a couple of years. As far as the whole where your man finishes… I had 3 partners during my time with Nexplanon. All would finish inside and I never even had a pregnancy scare. Now that’s not to say that someone else could be different. Technically Nexplanon stops ovulation so there’s not even an egg to be fertilized. In theory, you should never get pregnan.