welcome ang.
from what i know if its brown discharge it can be normal. brown tends to = old blood red = new. have you DTD (had sex) lately? or been more active. often in prg. the cervix has more blood flow to it so if there is a little movement EG sex it can cause a small bleed - but not so much it can affect the prg. KWIM?

I'm sure a much wiser BB'er will pop in and explain better then i have