Medicaid question

I can't ever get the lady on the phone. I've emailed her my questions and she said to call her and she would answer them but I have called twice and haven't heard back. So, I'm wondering if any of you have experience with this. My fiancé and I plan on getting married in March. Myself and our 3 kids (2 are his, 1 IS from my previous relationship in high school) are on Medicaid while he is on his parents still since he is only 23. While I was pregnant the last time I had to stop working bc of preterm labor so the Medicaid people looked at my fiance's income since I no longer had any and we are living together. Since it's my fiancée's income they're going off of for me and the kids, when we get married would he just be added to the policy and he become the head of household? Or do we need to look into signing up for Obamacare/Marketplace before it's too late? Mine and the kids insurance doesn't run out until middle of next year unless income changes. We live in Virginia, Im still not working bc child care costs too much for 3 kids (youngest is a newborn). Please help!