Confused beyond belief

My husband and I have been using the FAM for birth control for about a year now. We do use condoms and it's been months since he has ended in me, I get nervous with the thought of that. My periods have been consistently 34 to 36 days the last 12 months. This cycle I am pushing three weeks passed when AF was expected. Knowing how my body reacts I've recently been testing if I was pregnant the last couple weeks. Without a single being positive. I've been experiencing nausea very rarely, tender nipples and itchy boobs, and my husband mentioned that my veins on the tops of my boobs were super intense looking, he has never mentioned that before.