Weight and hair loss and i haven't had my period in 6 weeks, my norm is 5. if i'm pregnant (had sex 8 days ago) will it show up in the tests?

Probably not: if you had conceived 8 days ago, then at this point, your HCG levels will just start to be detectable on a pregnancy test from your BLOOD. Typical pregnancy tests use urine, and even if u had conceived as early as possible in your cycle, they are not usually positive until your next period is due,(until u have noticed that you have missed your period)