8dpo uterus pressure?

So we’ve been TTC for 5 months. I’ve been having mild twinges and cramping since 6dpo, a ton of watery discharge, and sore nipples. Today (8dpo) I started having frequent urination, my boobs are sore and heavy, and I swear I feel like a pressure is building inside my uterus. It’s on and off throughout the day it’s kind of feeling like it’s inflating? I took a test today and it was a BFN. Idk. I feel like every month I think I’m pregnant, but I truly don’t recall ever feeling this pressure before. Any advice?