Which one?

I have a question. I am buying a pregnancy test but I would like to know which one is more likely to tell me . I am 4 days late from starting my period. Getting cramps and feel a little like muscle spasm inside on left.
Headaches. Back pain, and somewhat tender breasts. I'm constantly tired but not enough to put me to sleep.. Which test can most likely give me the answer and recognmendations ?? :)