I'm confused

Hi everyone. So I've been on nexplanon since August 10 and I have either had little to no bleeding. So I get my pms symptoms like bloating and cramps right around when I'm supposed to be normally but no bleeding. I think I've spotted maybe one week or so and that's it. My doctor says its normal to have irregular bleeding but I'm still confused. Also before I got this implant I've never had one before. Are these things normal? And does anyone have advice to share with me? I'd really appreciate it.