Positive aPTT test. I need advise.

Married for 7yrs,MTP done(twin preg) D&C done in 2009. Latwr hav been doing my higher studies, and planned getting pregnant in 2015,Missed abortion D&C done (2 MA), took rest for 6 months and again got pregnant in jun 2016, had my scan on 6 weeks and fetus was seen with heartbeat, again scan at 8 weeks and could see the fetus heartbeat with growth, later on my 1st trimester scan their is no heartbeat seen and doc said that baby growth stopped at 8 weeks 6 days.,later declared Missed misscarriage and had D&C for the 3rd time on aug 2016. Doctor advised to take Torch panel test which came out normal, and asked to take PT and aPTT, Antiphospholipid antibodies IgM,IgG, Lupus anticoagulant blood tests- in these test all were normal except aPTT, aPTT 43 seconds. Doc saif that i can get pregnant again but i have to take an injection per day after seeing the heartbeat of the baby till my delivery,she didn't say the injection name Doctor pls help me with my next pregnancy,i need advise...