Is red bleeding at six weeks pregnant with no cramps a miscarriage?

I'm six weeks and one day pregnant with no signs if any problems until this morning i had some red blood after showering. It could be compared to a light period and only lasted a few minutes, then turned brown and disappeared completely. I had a pap smear five days ago and it was painful. My doctor said it is too early to tell anything and that i would have to wait four days until a conclusive ultrasound could be done. I have no cramps. Online searches seem mixed...half say it is normal while half say miscarriage. Has anyone experienced something like this---moderate flow of red for a very short time with no cramps? Thanks for any info.