17yo with Nexplanon and weird symptoms(TMI)

So I got the implant in my arm early May right after I finally stopped spotting with the IUD. After 30 minutes with tweezers in my uterus trying to find that damn IUD and finally pulling it out, I left and I never bled and or had a period since. About mid to late May I started having sex again without any protection and not pulling out, still to this day I don't have a period. I recently about a month ago had sex for the last time this summer and I haven't had a sex drive for a while, about a week after I experienced very soar and tender breasts suddenly one morning and its been at least 3 weeks since the tenderness has started. My breasts feel heavy and a bit hard, When I poop I also feel like my uterus gets bigger and something is pushing on my walls like there isn't any room. I cant get comfy in bed and I eat every hour and when I work and I see the food I feel this strong urge to eat it but I know I'm not aloud. I have no idea what is going on.