We dont hav any fertility issues that we know of but...

I honestly think that you just need to be ok with the idea that the age gap that you may end up with, may it be closer or further apart than you hoped for. Or that if you wait too long then it could be harder to conceive, you may need extra help with conceiving or it may be too late. Can you handle the idea of having two close in age better than the idea of having no more?
On the multiples front, well that could happen at any time, so realisitically you need to be prepared for that one too. Chances are more than likely low, but if it happened you could handle it.

But I do think there is a reason why that small part of you is screaming to start sooner rather than later. Listen to your body, it knows what it can handle.