Older age and autism. SO is freaking!

So my SO other and I have been discussing having babies for the past 4 or so months but more seriously this past month. He is 39 and has a 9 year old and I'm 24 and have an almost 5 year old. I was in the shot but only got 2 done and stopped because of the side effects. I then went on the pill with the least amount of hormones. We decided together though that I should be off everything and just see what happens. Then just the other day he found an article about how with his age and what not that our kids have a way bigger chance of having autism . Now he is freaking out about having babies and is having second thoughts. Then he changed his mind again and said because I love you . I'm just scared he will change his mind again. I need opinion!