(TMI) No period for 4 months

Roo
So in May I had started the nexplanon after having the IUD for 2 years. With the IUD from October tell the day I had it taken out I had 2 periods a month and constant contractions with excessive amounts of liquid discharge, the discharge was so much it would soak through my panties and onto my pants. In May I went in as soon as my period was over and had it taken out and replaced with a nexplanon and I had no bleeding since. Not even a week later I had a lot of unprotected sex as in no condom and no pulling out. For 3 whole months I haven't had a period at all. I mean could I be that small percent that dosen't have a period? I also feel like something is pushing on my bladder but I am assuming because I may just be bloated.. I lost 3 pounds I have no idea how because I am lazy and do nothing, I also have a little cold, a bit constipated.. I don't think and I am sure Im not pregnant and watch If I don't take a test I might be.