Confused

I had unprotected sex last week with my boyfriend on the 17th. He sad he came a little bit inside me.

Usually my period comes around this time.. in the 20s and I still haven’t got it.

Yesterday when I was at work using the bathroom I was spotting and now I’m not bleeding anymore. I’m definitely scared because i don’t know what’s going on. Is my period delayed, possibly missed.

How will I know if I’m pregnant and when should I take my test? I took a test today and it said negative, Should I wait?