Can dogs sense our sickness??

Me and my dog are very close. I have been in a lot of pain recently and I was just diagnosed with a pretty sizable ovarian cyst (I am currently undergoing further testing to decide how to treat). My dog has started laying on my stomach and absolutely will not get off unless I stand up. He’s a pretty cuddly dog, but he has been very attached to this one spot suddenly. I did a google search and found some articles that said dogs can sense when we are ill. Maybe I’m crazy but I just wanted to know if anyone has had a similar experience!! 🐶