Should I try? Please help TMI pic **

I had a miscarriage almost 3 weeks ago. The bleeding stopped 2 weeks ago. For the past few days I've had ewcm which is brown so I presume this is old blood. I've been tracking ovulation and this afternoon got a positive. The dr told me I could try straight away once I get a negative pregnancy test (got a negative this afternoon) and bleeding has stopped. This is so to avoid infection. Should I try tonight as I've got a positive opk and negative hpt test? I'm just a little concerned re the mucus - not sure if it's ewcm with old blood or miscarriage stuff?! Please help!! Xxxx