Do you think 39 is too old to ttc?

My fiancé and I have been together for 2.5 years, we are very happy together. We get a lot of criticism/judgement from people because of our large age gap. I’m 24 and he’s 39. He has a 10y/o son from a previous relationship, I don’t have any kids of my own yet. We both want another child. We were ttc for 6 months last year, then I found out I needed major surgery on my leg so we stopped. I’m mostly recovered from surgery now and we plan to start ttc again soon. We’re going to do it regardless, but I’m curious of what people think. We feel pressured to conceive ASAP because even if we were to conceive now, he would already be ~58 when the child would graduate school.