Pregnant

Is it too soon to get pregnant again? My little guy is my first and he is 14 weeks old now. I know most recommend waiting 18 months, but I don’t see any reasons for why- does this increase birth defects or miscarriages? My husband & I want a big family. In our opinion getting all of the younger years “over” with around the same time will be easier so that I can go back to work teaching full time again once our kids are school age. I’m going to be home with our son anyway until then, might as well have them all close together (ideally 4 children total, but I would probably space them out a little more as I have more children). My pregnancy was super easy, same with labor and delivery. Does anyone have any experience with having Irish twins? Nice comments only please, no judgment if this isn’t your cup of tea 😌