Terrified and Excited

I have decided to go off my birth control (after my husband and I talked, of course). Today is the last day it will be in my system. I have been so excited and planning all the baby things, up until a few days ago. Now I'm starting to panic, and second guess this whole thing. Is this normal? Did anyone else experience some serious cold feet? We decided to just "let it happen", so we aren't actively trying, but we aren't going to stop it, either. I know I have some control issues (I like planning things in detail), but the anxiety rising in me is worse than usual.