personality change in my chi

Question
hello...
my chihuahua is 4.5 years old, 7 lbs. super healthy and a good girl. she has been at my side 24/7 since we got her as a baby. she sleeps with me everynight, literally in my arm pit. for the last 4 weeks or so, i wake up in the middle of the night and she is gone...my husband has a computer room that he sleeps in on his late nights at work, which have been for a while now( 1 year?)...so this is where i find my chi, sleeping curled up at the end of my husbands bed by his legs.why the sudden change in where she wants to sleep?
this is actually breaking my heart:( she is my very best friend, as i am home disabled from working outside the home. i do have a sewing business i manage from home, so i am always here. anyway, my question is, why has my sweet companion suddenly left my side during sleeping hours?
did i mention she did this 4 years ago as well?
she would get up from my bed in the middle of the night and go sleep on my husbands chest for 2 months she did this...at which time we discovered/and my husband was diagnosed with Lymphoma...but is in remission now...
this IS ON MY MIND alot now...again.
thank you SO much for any advice or help you can offer.
sincerely,
tanya and emma D.

Answer
Dearest Tanya and Emma...your dog has already given a signal that your husband was ill.  It's quite possible that she is signaling again.  It is awful for me to suggest this, but perhaps your husband should visit his doctor for a thorough evaluation.  Meanwhile, do not despair that your much beloved companion dog is no longer devoted to you.  There's enough love in a dog's heart for everyone in the family.  You're one of a very few questioners in this forum whom I wish I could hug.