Questions... help! Could I be pregnant?

So I’ve had nexplanon I’ve never felt pregnant on it till now. I had it 3 years ago on June 11th had it replaced this year on June 6th! So yeah I’ve been dating this guy for over a year now. We never use protection & he has cam in me multiple times. But never have I felt pregnant. I took a pregnancy test about 2 weeks ago the dollar tree ones can back positive & clear blue & first response ones can all back negative. I haven’t been to the doctor because they were negative! I don’t have sore breasts. But I do have headaches, backaches all the sudden etc. I haven’t had my period ever since I got it in. Which I saw was normal because It happened the first time to. But even my boyfriend says I’m acting like I’m pregnant I’m not sure why maybe it’s the hormones that make me feel this way or i actually am. Should I take more tests? & which kinds? Or should I go see the doctor or do you think I’m okay & it’s just nexplanon messing with me?