Nexplanon, insecurities

I’ve been on nexplanon since March so nearly 8 months. And sometimes I still convince myself I might be pregnant and start to overthink and stress and feel horrrible. Jsut because I’m so scared of getting pregnant. My periods are irregular I’ll need for months then stop for a short period of time. But for example last week I started bleeding on Tuesday then stopped on Friday? Is that normal? Then get loads of cramps and feel a bit sick. Apart from that I don’t feel anything else? But the thought I might be pregnant still affects me mentally