I was 45 when we had our daughter - my concern is also the fact that I may not see her achieve as much as other Dad's get to, but ensuring I pack every day I can with Love, adventures and activitiesI was 43 and 45 when my children were born. I'm 47 in November and do have the odd thought about being an older dad. However, I don't really care and I look great for my age lol.
The only thing that bothers me, which I have no control over, is statistically I won't have as much time with my kids as a younger father should.