Oh it must be so frustrating! I find that as I get older I become less regular... so I lost trust in my regularity as such. My most accurate symptoms were as you described... the nausea and "fullness" around the bladder/uterus region. Also as you might remember with my situation last year, having a period also didn't necessarily "prove" anything either! It's so darn hard. I think ectopic would manifest as pain quite early... but I could be wrong.

Thinking of you!