3 kids?!

Hi everyone! I feel like I need some advice or opinions. I’ve been married for 3 years we have 2 kids and plan on buying our first house next summer. I’m currently a skin care specialist but would like to go back to school for more income but unsure what to study. my husband and I had a conversation today about expanding my family so the baby can be close in age with my youngest and would like to start trying within 2 months but I am extremely nervous!! Is 3 kids harder than 2? Do you still have a close relationship with your spouse? I kind of feel like it’s now or never i don’t know what to do.