Had sex during. Fertile window and three days before ovulation and I'm supposed to get my period Friday I took a test today and it was neg. Still chanc?

Yes. Wait another week and recheck pregnancy test if not bleeding. good luck.
Yes. It is too soon to say for sure whether you are pregnant. Check the packages for home pregnancy tests and follow the directions exactly, and the timing they specify. Until you know whether you are pregnant, assume you are: no drugs, alcohol, smoking, or over the counter meds, except for a multivitamin and folate (folic acid). Also, if you are not sure about your partner, you may have also gotten a STD.
Prob no- but.... Have you had your period yet? It is now 4 days late? That's not very late. If you have your period, definite no There are times when the pregnancy test fails, but if it is negative, it's not likely you are pregnant. The statistics depend on what kind of test you were using. Feel free to ask about the "sensitivity & specficity" of whatever pregnancy test kit you used. Someone here will know.
Yes. it is too soon to be sure. See if you have your period and repeat if you are late 2 weeks ( 1 if you can't wait)
YES-possible. however, your most fertiletime is 1 day before and 2 days after ovulation: having said that, yes. still possible.