6 weeks bleeding!? Pls help..

Rizona

am 6w4d today. Saturday morning I started bleeding a little. It was brownish discharge, so I went to my doc.she did an sonogram and we saw and heard the baby's heartbeat (142) so she said everything is fine with the baby. Told me to bed rest for a week. So I went home and today(Monday) morning I saw blood again on my underwear ,so I was scared bcs was more heavy.so i went back to my doc. She did and sonogram again and told me baby is perfect everything is fine ,but she doesn't know why am I bleeding, so she made me an appointment with an FMM to see if my progesterone are low. .so if anyone of you ladies has or had this kind of problem pls pls be free to share with me,cuz I am really freaking out, and can't even enjoy my pregnancy...