I definitely would recommend trying to find some sort of healthcare that you can afford not only for the cost of prenatal visits, labor and delivery, and any subsequent check-ups and immunizations the baby will need being so high but also to get yourself checked out. It could be something treatable, but there's a reason you haven't gotten pregnant these past thirteen years whether it's a health issue with you or with him.
Don't have sex daily (every other day is better to give him a chance to get his sperm count back up), avoid alcohol, eat healthy, exercise, maybe consider prenatal vitamins, but there's something that needs to be checked out.
I don't know where you live, but if it's in the states, your state should offer fairly affordable healthcare for your income range and tailored toward your needs.
Sweetheart, you need health insurance if you intend to get pregnant. Any complications for you or for the baby would ruin you financially. You think it's tough to pay for insurance, try paying for $100,000 in doctor bills and hospital care that are not covered by insurance. It can mount up so fast.