If you were pregnant and genuinely experiencing pregnancy symptoms, which are caused by hCG, that would generally mean there would be enough hCG in the blood to detect on a pregnancy test.

That said, I agree fully with loonylupinlover that the symptoms you describe are also potential side effects of hormonal birth control, and that between using condoms and HBC your chances of being pregnant are unbelievably remote.

I crunched some numbers once and found that the chances of becoming pregnant using both of those methods correctly is something like 1 in 50,000 over the course of a year... potentially even less.