help!

I'm 6 weeks pregnant and I've been spotting for 7 days before it was pink now it's red! Sometimes it turns brown but then the next day red again! I went to the doctor and they saw the baby and the heartbeat.. they said everything its ok and didn't give any meds.. I told the doctor if maybe I need progesterone and she said no because I've never had any miscarriages and it's maybe just my cervix bleeding but she didn't check it.. I'm worried since the spotting doesn't stop And I'm thinking I really need the progesterone to stop the bleeding? Can I buy it without prescription?