Don't know what to think

My boobs are huge and very tender, have been for days now. My sense of smell is ridiculous. I keep getting these dizzy/tunnel vision/ ringing in ears bouts the last couple days... but all the HPTs I've taken are BFN so far. I haven't had a cycle this long since after my second miscarriage last year. I am now five almost six days late. My Ava app confirmed O on CD 16 (normal for me). Now it keeps changing my predicted cycle start date...I don't know what's going on. Any insight?