OP, Matilda is such a lovely name. Congratulations!
I can imagine it is worrying but your husband has indeed most likely had it and not noticed.
My late father's side of the family were extraordinary people healthwise.
They all lived to incredible ages with very few illnesses if any.
My paternal grandmother at 70 was found to have stage 4 cancer and was given the option of palliative care or, because of excellent private health insurance, chemotherapy. We are talking over 50 years ago.
Unbelievably she experienced next to no side affects from the chemo, never lost her hair and made a full recovery and lived a fit and happy life until she died in her sleep in her late 90's....so lucky. At the time her oncologists said they had neither seen nor heard of a recovery like hers.
Some people do enjoy, through pure luck, very strong immunity.
Mine is good, but my 4 children have never required an antibiotic which is rare also considering their ages. I firmly🤞 believe they have gotten a bit of my grandmother's genes in them.
I think you will be fine and its highly likely your baby will inherit your husbands strong immune system too.
Keep posting here, when you feel anxious. Writing down your worries can be very helpful. 