How early do dogs sense pregnancy?

Does anyone know anything about or experienced their dogs knowing they’re pregnant before they did?

We’re TTC, and I’m currently 7-8 dpo and my dogs are super clingy!

I work nights and stay up all night the night before I work so it’s easier to sleep in the daytime. On these nights, they usually sleep with my husband in our bed. But last night, they both stayed with me downstairs. The same thing happened this morning. They followed me upstairs and got into bed with me and instead of following my husband downstairs when he got up to get ready for work, they stayed with me.

Our 13 week old puppy is currently snuggled right on me, and she NEVER does that. She usually takes my husband’s warm spot on the bed after he’s left for work. And our 1 year old dog is on the end of the bed. She usually follows my husband around all morning and watches him drive down the driveway through our bay window...but not today.

Has anyone else experienced this at all? Or even know anything about how early dogs are able to pick up on it??

*my favorite pictures of my super cute cuties attached for aww factor*