I have been having light brown discharge with a light bleeding when i wipe. pregnancy test said negative. what could it be?

Try again: This time let a gyn order a lab pregnancy test! good luck!

Probably period: The brown discharge was likely a light period. Brown = old blood. Repeat a home pregnancy test to make sure you are not pregnant. An "off" period from time to time is very common and usually corrects itself in the next few cycles. If it continues schedule a visit for testing.