Could i be pregnant?

I had sex with my boyfriend on the 25th of october. I'm currently 5 days late on my period. In the moring and some times at night i get nausea. I've had some stomach pain the past few days. I feel bloated and i have been getting really dissy, but when i took a pregnancy test today it can out negative. Is it to early for a test. Do i need to wait another week before taking another test. I don't know whats going on. Any advice would really help!