What could this be??

So I’m 10days late on my period, I’ve been nauseous and pains in my belly for like 3weeks?? I have the implant so I can’t be that I’m pregnant, my belly feels weird to the touch and I’ve had itchy nipples and there really sensitive at the moment, I told my boyfriend of 2years, and he thinks I’m pregnant but I just keep saying that I’m not and ill see if I come on this month. And today I felt like I was gonna be sick and I haven’t got much of a appetite🙄

Has anyone else had something like this??