Are you pregnant? If you are not pregnant, I would suggest you see a fertility specialist first. My first pregnancy was molar, the 5 following that would miscarry at around 6 weeks. I went to a fertility specialist and, though I don't test positive for the blood clotting disorder, the fertility specialist decided to put me on heparin to thin my blood. That is how I was able to maintain the 7th pregnancy with my daughter. I had a chemical pregnancy 2 years later. We stopped trying and this past summer I got pregnant without trying and I am currently maintaining this pregnancy with heparin again.
I would not say you automatically need heparin. You may need to go to a fertility specialist to determine if your eggs are developing properly, you are ovulating on time, and your luteal phase is long enough. Beyond that, there are other things they can determine by monitoring you. My fertility specialist is Dr. James Douglas (http://www.ivfplano.com/). My OB is in Frisco, Dr. Jason Harn (http://www.northlakeobgyn.com/doctors.html). Both of these men are amazing doctors and I highly recommend them and their staffs!