Miscarriage

Okay sooo I'm at risk for a miscarriage right now during my pregnancy i found out a couple days ago i was pregnant and I bleed red sometimes then it will go back to brown no pain or anything now I've been bleeding red since yesterday theirs no cramping thankfully I'm not in pain or anything I'm just afraid of the blood part what do I do my ob is closed till Monday! I think it's unnecessary for an er that would be money waisted I need to know like how does a miscarriage start how would you know your having one! Also I did have sex and exercise yesterday and it's a pretty good amount of blood no gigantic clots or anything and still have my symptoms.