Ok, first I agree with Specialmom. Second, I taught 8th grade for many years. That is one reason I asked about his birthday, because I have seen similar actions from kids who were young for their grade placement. Birthdays ranging from Aug. through Sept. for example.
However, the main thing I see is that you don't really know what is going on. Everything you have said is what you THINK might be happening. You say that, "I am afraid to approach the school and seek guidance on how to adjust this behavior because I don't want to make it bigger that it probably is." What you need to do is go to the school to find out what is going on. But, I also want to point out that the school year is very young. If he is at a new school, for example, they would have no clue. But since he has friends from elementary school. I would assume he has been at this school for awhile. Talk to his counselor. Just tell them you are concerned. The counselor can talk to last years teachers and find out a lot of information.
But, he is involved in 3 after school activities. That is perhaps what you should be looking at. Lets face it, you really have no idea what is going on at school. I can tell you from personal experience that, that is the way 8th graders like it.
Is this concern more because he no longer is telling you what is going on like he did in say - 6th grade? That is very common!
If he came directly home from school and did nothing but video games, I would be concerned. He has a very active life. My personal opinion is that I would not be concerned at all. And, I do hope that you realize that boys of this age start to separate themselves from their moms (and dads). It hurts. So support him in what he does. Let him know that you are there for him. Hope this helps.
Sometimes if kids have identity issues they behave like that. I'm not sure but down the road your son may come out as gay. All my gay friends had girl best friends growing up and felt comfortable hanging out with all girls no boys.
So, I have a son this same age and have always worried about him socially. He has some challenges and we had to really work on his social skills. One thing that I found is that kids can avoid social interaction for fear of failure. If someone was mean, bullying him, etc. --- they are afraid to reach out. This was the case at times with my son. I found it important to work on having a solid friend. I wanted many friends for him but even if he had just one, I would be okay with that. I fostered it. Can you do that? Plan something with one of his friends and make it happen? And if his best friends are girls, so be it. What's important is the connection and not the sex of the person that he has the connection with.
My son does not have a large group of close friends. His circle is quite small for his REAL friends. But he now has confidence and has many semi friends that he is friendly with. When he didn't have confidence, these acquaintance type of people were not really there.
Do you suspect he's being left alone by the kids or that he is staying away on his own?
And the BIG question . . . is he unhappy about any of this? My husband is a social butterfly and loves groups and lots of people. Neither my myself nor my son are like this. My husband had to readjust his expectations for our son to what was more his son's liking than his. Does that make sense?
Age can make a difference. What grade is he in and when is his birthday?
As long as his interest in school doesnt fade, there is no problem with his behavior. Make sure his friends are nice but if he is not a social person, he is just not a social person. I grew up the same way. I never really had friends because I never really wanted them. I focused on school, sports, and my rescue dogs. I am now 24 and have a good job, good apartment, never been in any kind of trouble, and I am happy. Some people just like being alone. Don't be worried, just make sure he does good in school, and doesn't surround himself with bad people and he will be fine.