Aww... how sweet! I'm kind of jealous! When our cat was pregnant a few years back she would lay on me and I could feel the kittens moving around all the time. As she got closer to delivering you could look across the room and see them move. It was the neatest thing.
When our Rascal had babies we had no clue that she was pregnant. It came as a big shock to us each time.
The first time was when we found out she was female. We thought we had two males. They shared a divided NIC cage and my daughter left a door open and the two were in the same cage the next morning. I was just happy they didn't kill one another as I really thought they were both male. A month later my husband comes running in when I'm in the shower and tells me "Honey, Rascal is a female". I asked him how in the heck he knew and he said "because she is having babies!". She had 10 that litter and they were all stillborn (what causes a stillborn litter?).
The next time we noticed her digging the carpet in the bottom of her cage. I was irritated that she was tearing it up so I moved her out of the cage and in to the hallway area that we use for the rabbits from time to time (where Thumper is now, awaiting his new NIC cage). I noticed her start to nest and I had read about false pregnancies so I just figured that is what it was. I wasn't concerned. Then I walked by and saw a spot of blood on the floor. I looked in her litter box and, sure enough, there were 7 little squirmy kits in there. I called my husband at work at 10:00 at night freaking out. He just laughed and said he was sure she'd take care of them. I gave her a makeshift nesting box and moved them over in to it (along with all the hair she had pulled out) and then changed her litter box. I was so worried about them all night but they all did fine. The next morning we told the kids about the new babies and my daughter had a sheepish look on her face and said "I forgot to tell you that we let Rascal and Bitsy have a play date and Bitsy 'played boy' with Rascal"
I was soooo careful to keep the two away from one another after that. We kept them in separate rooms even. The day before Easter my daughter went in to clean the cage and found 7 more babies in the litter box. I was so upset. We had enough trouble finding homes for the first litter (and we kept 2 ourselves). My daughter admitted to me then that she had accidentally let both out to play at the same time (forgetting one was already out). She said "but they were only together for a second" Yeah, kid.. that's all it takes!
I have to say though, all of those kits brought us so much joy and without those unexpected pregnancies we wouldn't have the 3 awesome buns we have now. Still though, it would have been nice to know she was pregnant so we could have made her a proper nesting box, etc.