Pregnant?

So I have a two year old already and since last June I got the Nexplanon implant. It’s been okay, not awesome but also not terrible. I usually feel like my regular self and have random bleeding, ALWAY after sex for about a week with spotting on and off for a week after that. Lately I’ve been feeling terrible. I’ve had headaches, my boobs hurt but my nipples hurt even more, I get dizzy and light headed randomly and I have absolutely NO energy. I’m not even sure when my next “period” is due. I’ve had sex lately and didn’t have any bleeding after which I thought was very odd. I took a test today and I’m 99% sure it was a negative. I’m going to test again in a few days or so. Has anyone else had this, or felt like this with nexplanon?