On the expired lovenox, just be sure that nothing has precipitated out of the solution. In other words, you shouldn't see any flakes or granules in the liquid. You also don't want to see any color change, or any kind of change from the normal appearance of the product, at all. Otherwise, as long as it looks okay, using it shortly after expiration is probably fine, in my personal opinion. (Bear in mind, I'm a patient and not a doctor or a pharmacist.)
For myself, I wouldn't risk using it a year or more later, though, because of the potential consequences. The purpose of the lovenox is to prevent blood clots, and if you were to get a blood clot because of bad lovenox, that would be serious, and it wouldn't have been worth it to save the money. I have discarded some expired syringes of Arixtra, which is a similar but more expensive product, for that reason. So if you're going to use this expired lovenox, do it now, would be my advice. Good luck.
Sometimes your doctor can supply you samples, but you an also contact the manufacturer of the company that makes the medication to see if they have a program (many do offer them) and apply for assistance and they may be able to help you. In addition, most pharmacies and Club stores in the US are now are discount cards, so this is another option.
I can't imagine that it would hurt you. You need to contact your doctor and explain that you can't afford the script. Help will come, I'm sure.