Anti coagulant injections?

Hi all, 
I've had two previous miscarriages and after going to see the reproductive doctor, he says that during my next preganany (took test today that was positive-eeek!) I'll need to inject myself everyday in order to reduce my chance of a potential blood clot that might cause miscarriage. I've read recent studies that have debunked this idea too. Anyone have experience with this?