The answer is almost certainly yes.
Many of us with a smart phone and social media have experienced having a "random" conversation with somebody only to be served ad's for that very thing on your Facebook feed minutes later.
The extent of this intrusion depends on the type of operating system your phone runs i.e. Apple iOS or Google Android etc.
Your powers to prevent it are similarly constrained.
Despite being a Fox News article, this actually contains helpful information on how to shut down as much of this eavesdropping as you want.
If, for example on your iPhone, you go to Settings >> Privacy >> Microphone you can see a list of the app's that have access to your microphone.
You, like me, may be surprised at which app's want access to your microphone for now apparent reason.
I have turned off nearly all of mine except for Shazam (music identification app') and Skype (video calling app').
It has definitely made a difference but the experiment is ongoing.
I am waiting to see if my heavy handed approach has compromised the usability of my phone.
I did also wonder how much, and if, it would improve battery life.
Of course, what's NOT listed is the iPhone's built in app's. How they use the microphone is anyone's guess.
Of course, the device is a phone, so if you want to talk to someone on it you are going to need yopur microphone to work.
So don't go too crazy turning everything off only to find out that you don't have a "phone" anymore.
There are lots of articles, videos and how-tos on this subject so I won't attempt to reproduce all that here.
This "listening" is something that has crept into our lives and we've kind of invited it in.
We love what the technology can do for us. It is exciting but we forget that behind it there are people and not all people are good...
... and even the good people stuff up.
Ever since mobile phones first entered our lives I predicted a time when it would become trendy to be disconnected.
Now we are connected in more ways than ever.
We buy devices specifically to listen to us and send data to the internet - Alexa, Google Home etc. So why would we be surprised that our phones are listening?
I am an advocate for turning off technology.
For my sake and the sake of the people around my phone often goes into silent, privacy and even flight mode.
I have to admit that fully OFF is rare but I am certainly not afraid to be uncontactable.
As you will see, if you read the article below, there are lots of ways to do battle with your phone over privacy.
I have to say I prefer to simplify rather than fight.
I see no point in putting my devices in a faraday cage or ruining them by putting stickers over cameras and microphones.
Just turn it off for dog's sake!
It is your phone. You're the boss. Not the other way round.
The article below goes into more depth and offers more information on how to fully block unwanted eavesdropping:
But remember you are unlikely to be completely on your own until everything is powered off.
Anyway, I'm off to buy a maternity dress 😬 (I think my phone has misinterpreted my weigh issues).