15 and pregnant...?

I am a sophomore in High school. I have a boyfriend I have been with for a while now. And well things got serious to where were having sex. I know we’re young. But I need advice. On January 2nd ( I know nice way to start the year) we had unprotected sex. Before we had sex I knew I was a about two days late on my period. I wasn’t really stressing about it since we had been safe the last time we had sex before January 2nd. On January 7th my mom had even noticed I was late on my period and made me take a pregnancy ( I told her I wasn’t having sex 😬) the test came back negative. It is January 11th and I still haven’t gotten my period. I am now 12 days late. I don’t know whether or not to take a pregnancy test now or wait a couple days. I honestly have no idea how to even react to this. I keep telling myself I’m not pregnant but a part of me knows there’s a good chance I am. I’m stressing out so much.