could I be pregnant?

So January I had brown cm I just thought it was my period. Last month my period is late by 30 days so far I have been having back pain and a headache every other day. My cycle day from the app says 46 days. The only thing is that all my pregnancy test I took say negative.  My cycle days are usually around 27 or 28 days. Haven't been on birth control since late November. And we have been having unprotected sex for almost a year. I'm crossing my fingers I'm pregnant but I want some advice:) thank you in advance.