Autistic teen, worried about toddler

Hi everyone, 

I am new here and looking for some advice and support. I have 4 children- a daughter 7 (with ADHD and learning difficulties but not autism) and three sons- 13 year old (dx with autism age 4), a 12 year old with no additional needs and a 20 month old. 

I am becoming increasingly concerned about my toddler, who still doesn’t talk (he used to say words but now doesn’t), seems to have “absences” and just generally concerns me. The problem is that I struggle to say why! 

My husband (who is very supportive) thinks I am anxious because of my eldest son but I feel like it’s more than that. I didn’t know that he was autistic when I had my second son so it wasn’t something that concerned me, and my daughter (who is adopted) was brain damaged in an accident as a baby so I knew there would be complications there, and there’s no genetic link between her and the boys. So it’s possible he is correct and I am paranoid as the youngest is the first baby I have had to worry about the genetic link with. 

Is it normal to be fearful when you already have an autistic child or should I follow my instincts and speak to a health care professional? 

My husband is brilliant but he isn’t the father of the eldest two children so he didn’t know my eldest as a toddler and wouldn’t understand how it all felt, if that makes sense. Sometimes I feel like I am still sad about my eldest having autism but I could never admit this as I am known as a “coper” and can’t really express my true feelings. 

However, my toddler definitely does things his brother did not- cuddles in to me, puts his arms up to be held and sometimes answers his name. So I keep swinging from being concerned, to reassuring myself, to worrying again. 

Can anyone help me, I am tying myself up in knots. 

I promise I am more sane than this ramble makes me appear!