Back on the TTC merry-go-round

This morning I saw my doc about TTC #2. I just wanted to check with her if she thought I should go back on metformin, as I was on that when I was trying before. Well, it turned into a full pre conception check, and she's ordering loads of blood tests, advising folic acid, and recommending another mmr shot, and flu vaccine. Aaggghhhh!!!! I so don't want to get back on that TTC merry go round. I wish I could just wake up one day and oops! discover I'm six months preggo with a perfect baby. I wish TTC wasn't so stressful. I wish there was a guarantee. I am so blessed with my beautiful baby girl. She turns six months old tomorrow. My ob told me if I want a second, to start trying when she is six months. We're here already? I'm 43 now. I am so fulfilled with just her. I don't need another. But it would be nice, and would be so great for her to have a brother or sister. Am I tempting fate???? Or being greedy?