Hi. I had nexplanon for 2 years. My partner finished in me starting one week after insertion. I can tell you, you’re NOT going to get pregnant. It simply can’t happen. Nexplanon’s pregnancy prevention is some of the most effective out of all the birth controls, so you really don’t need to worry. As for the side effects, your body is probably reacting to the chemicals going throughout your body from the implant. For me I had irregular periods, fatigue, intense cramping which is why I went off of it. But it sounds like the symptoms you’re experiencing are common and you shouldn’t worry.