Be realistic: If things go poorly with your early pre-med classes, re-evaluate whether you have a decent shot at getting accepted before you get in deeper.
Hedge your bet, at least at first: Keep your options open. If you are working, consider working part-time until you have a few of the big pre-reqs completed.
Know what you are getting into: Talk to med students, residents, and practicing docs in different areas (not just OB/Gyn). Ask them for the positives and negatives. Shadow folks in a variety of medical roles; perhaps you will find PA or some other option more attractive. Volunteer in a medical setting. Read articles about MDs' appraisals of the field, such as this depressing nugget in the NY Times:
link. There's a lot of unhappy MDs out there. Consider what it would mean to you and your family if you are one of them after such a long training process.
Think long-term: This journey from being a non-trad going back to do prereqs to a practicing physician is an incredibly long one. Think about how many years you will be committing to your training, not just the four years (or more) for med school.
Look at the financials: Figure out if your family can handle the loss of your income and cost of pre-med and med school. That's a big stretch of negative cash flow. If you already have a ton of debt, you might be digging too deep a hole.
As for your major, I don't think that's important. I was a Poli Sci/Comp Lit major and had a law degree. That would not have mattered had I not done well enough on my pre-reqs and MCAT.
Good luck! I hope you find the way to your dream.