I need your advice!!! Please and thank you :)

Hi! Sooo.....I think I ovulated around the 23rd, and I had blood on the 29th. Af is due on the 5th. My issue is, I am scheduled for a ct scan tomorrow morning, they did a pregnancy test on Thurs the 28, negative (obviously too soon, knew it would be even if I am preg!)....my question is will these 4 days make a difference? Do I do the scan and assume I'm not pregnant for sure and wait for af? I don't want to poas because I tend to get addicted and emotional when negative. I'm not feeling pregnant but I don't feel af either...I called and told the nurse and im sure she pretty much thinks I'm crazy -_- TTC shouldn't be this technical lol!!! Tyia ;)