Pregnancy Timeline

So I have an odd question. I want to slowly buy things for my baby over time, then once I'm actually pregnant, but thing big things like a crib and car seat. I want to do this before so that I'm not doing it while pregnant or caring for a baby. I know a lot of stuff you don't need, but I want to be prepared. My significant other, however, wants to wait until I'm pregnant. How do I compromise?