Best advice is carry out the doctor's orders.
I recall when my wife had major cancer surgery we had to inject a anticoagulant, and I asked about just using Warfarin. The doctor said no, it seems the injection is far more effective (strong?). I don't recall how long she had to take the injections (administered by me), but think it was about a week. I also recall when I picked up the box of one-use syringes I said, "but we have prescription insurance".. he said, yes, that is your cost after the insurance covers (a major portion of the cost) its limits. I guess there was no generic substitute at that time (about 2 years ago), the throw away syringes couldn't account for more that a dollar or two per shot. The good news is she didn't have any clot problems, that we know of.
I'm sure you have looked up the list of symptoms on stroke so I'll not try to do better as I'd have to look up myself. Happily I have never had any stroke problems, that I know of.
Keep us posted, we all wish you a speedy and full recovery and atrial fibrillation free life.