@Ric****
You have to be really careful man, if you overstay more than 90 days you'll get blacklisted for 1 year. Month is a long time. I wouldn't go to immigration yourself, I'd let an agent contact them for you.
Also, once your child is born you'd be eligible for a Non-O based on having Thai family. You have to make it here that long though and don't get blacklisted.