Sadley since you have had blood work done,and all tests have come back normal.they will say 1 in 4 mc.with no explanation,usually chromozones.back pain is common in pregnancy.I know how you feel after multible mc, myself.Every little thing i feel maybe sign of mc.but your not bleeding right now which is good,definately talk to your doctor,to have your levels checked,however there is no medication that will prevent a mc,whats meant to be will be.they could check your progesterone level etc,and if low then maybe put you on progesterone,but understand if pregnancy is not viable,progesterone will not safe it,but delay the unevitable.until you can get to your doctor then get plenty of rest,drink plenty of fluids.good luck..
During your OB's business hours make a call and ask them what they'd have you do. What are they doing to prevent another miscarriage? Are you on Prometrium (or another progesterone supplement)? Or taking baby aspirin? There are some preventative measures to take to prevent miscarriage if it is recurrent and they know why you keep miscarrying (depending on what is going on).
They need to check your HCG levels. They should double every 48-72 hours.
They also need to check your progesterone. Anything less than 20 should be supplemented because of your history of having a couple of miscarriages.
Please let us know how it goes!