How do I know if I’m pregnant?

Hey guys so my period has never been normal ! It’s super weird I could get it once a year and not get it till the next year . I already went to the doctor for it and they told me it’s normal . My last period was October 2 and impretty sure I’m not going to get it anymore. I had unprotected sex with my boyfriend last week for the first time and he came in me . So it’s hard for me to see if my period is late .How do I know if I’m pregnant?