brownish discharge

i know this might be a little too much but i need some advice or to see if any other momma's has had this happen. im currently 6wks pregnant. with my last two pregnancies i bled the whole time. which resulted in the loss of my babies. 1st at 22wks & the last one at 13wks. This time I have stopped smoking cigs as soon as i found out i was pregnant. But the past cpl of days my discharge has changed in color from a white color to a yellowish brown color. I told my doc about it this morning & he said its normal. but it doesn't seem normal to me. Has anyone had this happen? should i be expecting the worst again? thank you in advanced.