Does anyone know what it could be?

Okay so I am a big girl, and I check my pelvis by lifting my stomach up. Well you ladies know that I didn't have a period for three months and just got off the one I just had. I did have a faint positive and three negative HPT. Well here is where I am freaking out. I have noticed that my pelvic is getting hard. And when I left my stomach up you can see a bulge. 
​Can you please tell me what you think?