so frustrated

I lost the weight (mostly) but suddenly it's popping back up again. 

I don't get a period and I do have  symptoms similar to when I was pregnant with my daughter. But I tested and it came out neg. I don't know if the implanon birth control is causing all this or what. Sure weight gain can be a side effect but I'm only 112! Why is it all in my tummy? I've been eating better and exercising but this is how I look still. And FOUR people in the last 2 weeks have asked me if I'm pregnant. When I say no they ask if I'm sure. (They all mean well) 

What's going on???!? 😢😢😢