Hi C.,
I just gave birth to baby #2, who is just over a year younger than my oldest, and I am in school working on a masters degree. I do not have any family help, other than my lovely husband, but we do have a good nanny. Here's my advice:
1) Find out what services are available at your school. You most likely have a health center, where the care is normally free (or rather covered in your semester fees) and you can certainly get a free blood test. Also, if you are in fact pregnant, you can often get HEAVILY discounted childcare for your newborn through your school. However, due to the high quality of this care, and the cheap price, there are often long waiting lists. My advice is to put your child on the waiting list for childcare before s/he is born. Lastly, as far as on-campus resources are concerned, your school may have a women's center where you could get some much needed support and perhaps some assistance with navigating community services.
2) My guess is, if you are a family of four, that you will easily qualify for Medicaid and WIC. I'm not sure what state you're in, but I have worked in healthcare and I've never heard of someplace that does not have special circumstances (that is, they will provide insurance for you when they otherwise would not) because you are pregnant. Incidentally, if your child is born while you are on Medicaid, they MUST (under federal law) be covered by your state through their first birthday. If you cannot get a blood test through your school, your local Medicaid office is often very helpful with getting you care at a free clinic. Most people in public assistance truly want to help you and your baby. While you are at it, apply for food stamps and WIC.
3) Maternity clothes... I was lucky and listened to my husband when he suggested that I keep mine. However, all hope is not lost. Again, I don't know where you are located, but when we lived on the west coast, we could find really lovely (and name brand) maternity clothes at Buffalo Exchange's kids store and where we now live in Florida we have a local kids store that sells used kids clothes and toys, as well as maternity clothes (again, name brand for cheap). If you don't have any stores like this near you, you can try craigslist on-line and try to buy for cheap, but the best resource is freecycle. If you sign up for your local freecycle you can post requests (like HELP I NEED MATERNITY CLOTHES) and people will respond with free gifts. I have gotten BAGS of children's clothes, like new and name brand, for free from folks that just want them out of their house.
Okay, hopefully this helps! I know the panic of an unexpected baby. Hopefully your preganancy will go easier this time. My faculty were very understanding of my needing to miss a couple of classes here and there, and to skip out on some of my teaching responsibilities as well. My first son was induced two weeks early and everyone understood. If you are still working as a notary, just be honest with your boss (but wait until 2nd trimester to tell them). You do have rights in the workplace, but they vary from state to state. Learn what yours are and hold your employer to them. Good luck and DON'T WORRY. These things have a way of working themselves out!