Baby not smiling

[NinaPS]

Hi guys, km not sure if I've posted in the right section so please advise me if you think it would be better off under a different topic.
My son is 8weeks and 1 day old, he was born at 37 weeks and 1 day. My HV rang on Wednesday for his 6-8 week check (no face to face due to current pandemic) she asked me a bunch of questions to assess his development and in those questions she asked whether he had smiled yet, to which I responded no. She also asked whether he was coping (making ooo and aaah sounds) and again the answer was no. She said she would 'usually' expect a baby to have started to do both of these things round about now, and she will ring back in a few weeks to see whether he has started. Should I be concerned? When did your babies smile and start to baby talk? I feel completely paranoid now watching him every second to see whether he smiling and attempting to stimulate him with sounds and images and just generally talking to him to try and get a reaction out of him. Borderline obsessive!

Meh there is debate over whether newborn can copy imitate
www.sciencedaily.com/releases/2016/05/160505133848.htm

Do you think baby can see and hear you?
Do her eyes follow you?
Wait a week or so

My 2 eldest DC's were born at 37 weeks and I'm pretty sure neither were smiling at 6 weeks. By 9 weeks (equal to 40 weeks plus 6 weeks) I'm pretty sure they were. In fact they both did thing a couple of weeks later than the babies born at 40/41/42 weeks. I remember being slightly anxious about it at the time. Fwiw, they are both teens now and very smiley.

Ds1 didn’t smile till about 12 weeks (quick to talk but didn’t walk till 2 years old)
Ds2 was born smiling (but slow to talk/ quick to walk)
Ds3 9 weeks to smile
... they’re all different. They all do things at other times. Please don’t worry. Mine all did things at different times but they’re all perfectly fine. My niece didn’t smile till she was 2. Bil was really worried. She’s a content sociable 6 year old now. They are all different.
This is coming from someone who has waste a lot of time worrying unnecessarily. Please don’t worry.

DD2 I wasn't certain she'd smiled until about 4 months.

Dd1 smiled at 5 weeks. Big beaming grin, repeated it the next night, and then was very smiley.

DD2 just glared. I wasn't certain she'd smiled for so long, and I did worry about it. She was just less smiley than dd1 as a baby. However dd1 grew into quite a serious toddler, and dd2 became very smiley-first thing people commented on.

Ds smiled at 1 week. Very clear smile, I was really surprised. He'd smile at anything with a face from soft toys, pictures through to real people. I put it down to being #3 and just thankful for any attention.