You can take a home pregnancy test.
You cannot make a period arrive more quickly than it will.
The MAP may or may not work after 4 days -- it works best taken within 3.
It may or may not interfere with your normal cycle.
And any other questions about it, at this point, would need to be addressed by your doc, like it or no.
Editor and Founder, Scarleteen
My epitaph should read: "She worked herself into this ground."
-- Kay Bailey Hutchinson