Hardness in pelvis area

So I've been feeling extremely bloated to the point that it actually feels like there's a hard ball in my pelvis area. I don't usually experience this as sign of AF, I've been pregnant twice already and can't remember experiencing this durning any of my pregnancies. Also I'm 12 dpo and have been testing since 10 dpo and they were BFN. What do you guys think this is? Have you ever experienced this?