I know that pregnancy tended to destabilize me. For others they never felt better. You'd want to be followed very closely during and post partum. What meds can you nurse on etc.

You should see if your feelings about your other kids are separate from wanting another baby. Really take a few weeks or months of sorting this through. If you're as fertile as you say, this short amount if time won't matter. You could even still look up sperm banks while you're thinking.