Hi R.,
Good for you for staying home with your child! I had to go back to work when my daughter was little, but by the time she started Kindergarten, my husband and I had to figure out a way one of us could stay home.
That was the year we finally found out she had Sensory Processing Disorder--so she was special needs (which we knew already, we just didn't know what she had!). She'd already been going to doctor visits, specialists visits, extra OT/PT visits, not to mention my own dr visits--and then there was going to be the days off school, the days she'd end up home being sick, the winter break and spring break vacations, etc.
My husband was in sales at the time, and there was no way I could count on him to be around to take time off work for any of that stuff. Plus, my job paid for day care, health insurance for me and my daughter (my husband worked for a self-insured company that, if you worked somewhere that offered health insurance, you had to take that over his company's insurance), my parking spot at the university, and my 401k. After that, there was no extra money. So staying home, not paying for health ins (went on husband's), day care, a parking spot--well, let's just say, it was tight, but doable.
That was 7 years ago. My staying home was the best thing we could have ever done for my daughter. Her anxiety level went down, she concentrated better on her homework, knowing that I was always there/around, and we were able to concentrate on therapy for her SPD.
What it came down to was deciding which of us--me or my husband--had a skill that could be used/turned into a work-at-home job. I have been involved with writing and national writing organizations since 1993; I have a BA in history, Spanish, and German. My husband has a BBS in business/accounting. He has worked in industrial engineering, HVAC, electrical, energy conservation, and commercial/industrial construction; he had/has the potential to make the money to support the family.
So it was decided that I would stay home with our daughter, take her to her doctor appts/help her with her SPD, and start my own company. I have had a contract freelance editorial business now for 7 years; I work as a content editor for an e-publishing company editing fiction books and as a proofreader for a small book publisher (again, fiction books), specialty romance books.
It doesn't bring in a lot of money, but it has allowed me to stay home with my daughter and has given my husband free rein to keep developing his specific areas of interest and continue moving up/around and getting into higher positions with different companies around the region. Working/owning my own business also lets me put on a resume that I've been working since I've been home with my daughter--a big, big plus.
Can you take any of the knowledge you gleaned/used in the medical settings you've worked in and turn them into a home-based business, or maybe into contract work? I know there is WPS, a health insurance company in my town, where you can train for 6 months at their headquarters and then, when the training period it over, you can do the work from home. However, that is an actual job; if you did something like that, you would need to dedicate specific hours every day as well as either having your son in daycare and/or having someone come to your house to watch him. Maybe. It depends on what you're doing. If all you're doing is inputting on the computer, if he were older and could entertain himself, then that could work.
It isn't easy finding something that can be done from home that can also be done around childcare/raising your child. I like contract work because I do the work at my own pace; I also didn't start my company until she entered kindergarten/started school. My daughter is now in the 7th grade. I try to get my work done during the day, so I have evenings and weekends open for family. However, there have been many times when a book has got to get edited and I'm working nights/and or weekends. But I can shift/move around when I work, when I run errands, etc. So there are many, many variables to look at.
Where my parents live, there used to be a company that had a program where you could count rebates (they were a rebate center) and you got paid for so many hundreds or thousands of rebates you counted and batched. There are some companies out there who usually use the handicapped to stuff envelopes for companies doing mass mailings; sometimes they'll allow people to do this in their homes. A small town by us has a mass-market flower company that, about 3-4 times a year, looks for extra people to come in and put together flower arrangements (think Valentine's Day, Sweetheart Day, Mother's Day, Thanksgiving--big-time events where flowers are bought/given). I did that for a while. However, in order to make the big bucks/hr, you had to put in a lot of hours. That one you would have to go there and do the arrangements at the warehouse, so you'd have to have someone watch your son. But if you did well and they liked you and your work, you could get on the roster for when they needed extra help.
Really, seriously, you just need to start looking around your community and find out what type of work is out there and get your name out there as looking for part-time, fill-in help. Pretty much any type of job you'd do from your home will involve you leaving your home to go do it (I'm thinking selling, like Longaberger, Mary Kay, Pampered Chef, Tupperware, etc.) unless you have something specifically set up that you can actually do from home.
I'd look at your job skills, then look at what would be marketable that might have a potential to be a work-at-home situation, then find out how you can make that happen. While I love editing, at the moment I'm looking at additional ways I can bring in income and have started looking at other things I can learn to take classes and get accrediated for (at the moment, I'm looking into a possible herbal clinician class I can take to help people with natural ways of healing themselves; it's a 3-year program. Now I just have to decide if I can afford to do it).
Good luck!