Brown discharge one day after vaginal ultrasound?

Yesterday at six weeks I had a vaginal ultrasound. My doctor said everything looked good for where I was and my hubby and I even saw the baby's heartbeat, which was awesome. This afternoon though I saw some brownish discharge when I wiped, which freaked me out. I haven't spotted at all so far and was wondering if anyone else had some minor brownish discharge after a vaginal ultrasound? It would make sense to me because the doc was really pushing that probe all around but wanted some reassurance if anyone else has gone through the same and then been fine? I'm not cramping and my doc said to just call if the discharge increased.