M., take a deep breath. It's always disconcerting when our own kids don't seem to be doing what their peers are doing-- this often sets parents off on red alert. First of all, it's highly likely they are 'just fine'.... but lets say "what if...." because you seem to be concerned about the unknown.
It's hard to diagnose autism in a child as young as yours are. That said, you are right, there are specialists and this may be either a short or long path for you. You could wait another 6 months and see a lot of development, but lets say you don't want to, or that you wait for months and your fears feel more and more confirmed. An evaluation and information are the best ways to deal with that worry.
My first word of advice is "be okay with this path". Results sometimes take a while to receive. Appointments-- sometimes you have to wait a while to be seen. So, please, don't let your sense of urgency keep you from being present and enjoying your boys.
Second piece of advice: when you decide you want the evals done, don't wait, talk to your pediatrician and get the ball rolling. You may likely need a referral from your pediatrician for insurance coverage purposes. When you get a referral, call the facility and talk to the intake coordinator. They want to help families and these conversations have saved us a lot of out of pocket expenses.
Ask when you are unclear about something: a cost, a procedure, an evaluation, an aspect of the evaluation, a technical term. The staff want to help parents understand what's going on, both financially and with their child. Don't feel afraid to ask questions, and do a LOT of active listening. It may be wise to have your husband or partner there to help with the kids after evaluations/when receiving information so that one of you can focus on the information while the other tends the kids.
Again-- be okay with this. I have a child for whom this journey started when he was 4. (He has ADHD-inattentive and some significant processing delays.) I'll admit, it's a different world entirely. Parents of special needs kids deal with a society which largely has a tendency to blame parents or not understand certain issues. (for example, our school district has a panel on autism and lots of education in that regard but nothing for ADHD other than "have you considered medication".) Early on, our preschool teachers told us they suspected a non-verbal communications disorder which was 'often found in families with only children'. There are non-professionals and professionals both who may insinuate that if you parented your child differently they might not be as impacted as they are. There are people out there who confuse abilities with idea that the child actively chooses a certain behavior which that person finds problematic. So, if you do get a diagnosis for your boys, understand that there is a sea of misinformed/under-informed people out there who need to be educated on your child's diagnosis and educate yourself to be your child's best advocate.
I should add, one of the kindest things I have ever heard toward my son was from his second grade teacher, who thrived on his own education regarding brain function and learning. "We often believe it is okay for a student to have a challenging teacher; it's also okay for a teacher to have a challenging student. There's nothing wrong with that. It's a challenge and that's how we grow." That message of grace and the understanding that education/interaction is a dance between the child and the adult is a philosophy I've come to live by. It gives me permission to feel challenged and to recognize that it's okay I'm not a perfect parent. I'm just working on being the best mom I can be for my own kiddo. It's also created a standard in my own mind as to what 'quality' is as I continue to grow this child up. So often we are told to see the child as the primary problem and that neurotypical people are the 'norm', so that any problematic incidents are the fault of the child. There has to be receptivity on both sides and the adults are far better able to make small adaptations initially than the child is able to analyze and try to cognitively puzzle through how to change their behavior (without the benefit of mind-reading) so that the adult is pleased with them. For the most part, all of our kids respond to positive feedback and want to please adults, so for many adults, they are in a much better position to influence positive behaviors than to expect a child to change what we would consider a 'negative' behavior.
Don't shy away from an diagnosis or 'label'. I've seen children suffer incredibly because parents weren't open about the child's challenges or were afraid that the label would influence how people treated the child. It's just a word, it's information. You can be sensitive about who you share information with, but if there is a dx, the child needs their parent to advocate for them *before* there's a social or behavioral hiccup with other children, teachers or caregivers. One parent I've known refused to accept her child's ADHD and to get help for it when he was younger. He suffered as a learner (because educators did not have strategies for a kid who appeared 'lazy' and whose parent did not inform them otherwise); he suffered in feeling poorly about himself as a learner. Only in his teens did his grandparents take over parenting and found successful therapies for the child. One wonders what sort of potential might have been open to this child if only he'd learned early-on about himself that he just *learns* differently? If you were going to drive a new car, you'd want to know if it was a stick or an automatic, right? Educators and caregivers will want that same info about your child, not to be nosy or judgmental, but so they can best help your child. One child we know is very physical-- even violent-- toward other children. The parents will not discuss their child's autism, which leads to other parents being very angry with the child for the harm to their own kids and the impulse-control issues which they witness. (In that case, when the student's parents didn't actively advocate for their child, a number of us parents DID insist the school provide a para-educator. Too many of our children were getting hurt AND it wasn't fair to the boy in question, either, not to have help.)
Lastly-- your kids are amazing. Every single child comes with strengths and challenges. I used to teach preschool and can tell you, that was my experience. Each child is their own person, full of their own beauty, quirks, knowledge, kid-wisdom, funny moments, so full of life! In my journey thus far I've learned to let go of my hope that my son would be typical and 'on par' with his peers.... I now celebrate the unique facets of his personality. I've worked over time to adapt to parenting styles which work for my kid. (some of it flies in the face of what we consider 'good parenting', by the way-- but it's good for MY kid and he's positive in his responses). I won't say it isn't hard or that there won't be hurtful moments-- there have been some and there will be more---- but choosing to appreciate my sweet, glorious kiddo for who he is *right now* is the best vote of confidence I can give him. And that is more valuable than anything else I have to offer: my faith that he will be just fine as he grows up and matures into the person he will become. That he will find ways to adapt and learn to manage himself in our world. So be present, enjoy them for who they are in *this* moment, learn to understand that the label doesn't change who they truly are. Wonderful human beings who need a lot of support and guidance, just like any kid, anywhere.
I know this is a lot to take in. Please know it's just another journey in life, you've got to walk the path to know it. There's no other way to get this sort of education-- I'd worked in early childhood ed for nearly 20 years or so before I started down this path, and it's changed so much of my thinking as I learn. I don't parent at all in the way I would have expected I might, but I still do so with love and appreciation for who my kiddo *is*. Best wishes.