Is it common to have brown discharge as a period while on clomid (clomiphene)?

Not necessarily: The period when taking clomid, (clomiphene) if the Clomid (clomiphene) caused ovulation, is usually relatively normal. If there is only spotting it is possible that ovulation didn't occur, and it is possibly implantation bleeding with a very early pregnancy. If the spotting doesn't become a regular period in several days checking a pregnancy test would help to clarify.