Okay, do NOT let anyone, tell you your baby is too clingy. THEY need to be aware of developmental changes in a baby, which they do not seem to be aware of. They need to get educated about these things.
First of all, a baby goes through "separation anxiety" at this age. It is NORMAL and developmental based. It is ALSO normal, that a baby gets clingier when they are tired or hungry. NORMAL.
It is also normal, for a baby to show a preference for either Parent or caregiver.
It is also normal, that a baby prefers the Mommy...afterall, she is the one they bond with first...it is a biological and instinctual and normal baby behavior. A baby can even "smell" their Mommy and identify her...that is how strong the instinct is.
Both my children were like that. My Hubby and Mother never questioned it. It is a phase, and shows that the baby's "survival" instinct is differentiating between their Mommy and others.
Babies ALSO go through "stranger anxiety." And a natural preference for those that they are comfortable with. It's a baby's natural sense of "safety." (separation anxiety and stranger anxiety can be researched on Google, it will tell you all about it).
I would recommend that you not "change" your parenting per say, just to suit them....BUT, at least look at it objectively, and see where and when you "could" provide your baby with "independent" moments which helps their sense of self and development. NOTHING is wrong with your baby or you. Your baby just has a strong bond with you, nothing wrong with that. HOWEVER, you can try and let your baby have time to play by himself, and explore his surroundings without being carried all the time, or assisted. Of course watch for safety, but it's fine to let a baby roam and explore and play independently, while you are close by supervising. (I'm not saying you do or don't do this.)
All babies have their own temperament and personalities, and needs. My firstborn was very clingy, my second born is very independent. Every baby is different. For example: If your baby cries...sometimes, you can try and soothe him with just your voice first, even though you are 3 feet away. Sometimes, they are just temporarily crying. BUT, if he is really in distress or upset, sure, comfort him. That way, they will "learn" that you are right there for them. That's what I did with my firstborn...I'd be right there in the room with her..but let her play by herself, so that she got used to that instead of expecting me to be 1 inch away from her and carrying her.
It really depends on what the situation is... nothing wrong with attachment parenting. I still do that with my kids and my girl is 5, and my son is 21 months. But, I do it with their developmental and age appropriateness in mind.
Oh, ALSO... as a baby goes through developmental changes, there is also something called "object permanence" ...this is the concept that things go away, and comes back. ie: peek-a-boo games etc. As they are going through this cognitive recognition...they may sometimes get upset if they can't "see" Mommy if she walks away or is just around the corner. But, this is all developmental.
A great book (perhaps to have your Hubby and Mother read), is "What To Expect The First Year" by Arlene Eisenberg. It is really great and explains the month-by-month developmental changes in a baby.
You're doing fine.... and seem like an attentive and very caring Mom. Don't get self conscious. Perhaps, your son will "outgrow" this clingy phase... or it could just be his personality. No worries.
All the best,
~Susan