What/when should I tell work?

I am currently 30 weeks pregnant and work full time as an assistant personal manager. The position is fairly knew, it was offered to me even after I told my bosses I was pregnant, so they knew I was going to be out for a few months on maternity leave.

My husband and I would like it if I could be a SAHM while he works from home full time(IT help desk for hosptials)to avoid daycare. Family is not really an option for us as most of them are far away or not yet retired and have time to stay with the baby. I would like to avoid daycare as the price is just outrageous and we both don't really trust strangers.

I told my boss that after maternity leave I would be coming back part time, I didn't think it would be a good idea to tell them that I was planning in quitting.

I have a great job, and I have amazing benefits as my job pays for 100% medical bills, to make sure I don't have to pay it all back after the baby was born I want to work for at least a month and then leave.

Long story short: I am planning on putting my 2 week notice in after a month back from maternity leave, does this sound smart? I feel very guilty leaving them, I love the people I work with, but my job commute is almost an hour away and both of us think it would be best for the family.