If you got pregnant in Feb 06, then I assume your baby was born in Oct/Nov of 06. That only puts you at 24/25 months postpartum. While it's not common to go 2 years pp w/o a period, it's definitely not unheard of and doesn't mean that anything is definitely wrong.
I realize that this may be the longest YOU have ever gone..but it is still within the range of normal. Could be because your youngest is nursing more than other children, or maybe just that you are older (aren't we all
) Just because you ahve always gotten fertility back earlier before, doesn't mean that you will this time. Plus, I have read that fertility tends to come back later the older you are. Of course, I have no idea how old you are...but it is obviously older than you were 3 years ago.
I know it's hard when you want a little one so bad...I'm sorry you are stuck waiting.