Help please! Weird symptom.

I've been having symptoms all week like bigger, tender breasts, feeling nauseous and change in taste buds amongst other things. Today I've been having severe pain just below my navel especially when I lean back or forward. I'm 12 dpo and due tomorrow. Has anyone ever had this? I've only had negative hpts so far. The pain feels like it's going down in a line towards my nether regions but stops just before my pelvic bone. Also really bloated - slightly more on left hand side. Any responses would be hugely appreciated! Quite worried.