We recently adopted a stray female cat and found out only a month into it that she was already pregnant ( pretty sure she was pregnant after we got her as she never had any outside contact thereafter ). Went to the vet for ultrasound and I think we could be expecting 3-4 kitties. This morning I knew she was about to give birth as she was agitated, kept circling around the house, and was noisier than normal. Well into the afternoon, she shot out a kitten like a canon ball. This is both our first time, but I knew I shouldn't intervene as much and just watched her lick the kitty, and eat the placenta. After a while, she took the kitty and hid her at an area in the house that's quite difficult for us to reach. It has been around 3 hrs since she went in there and I haven't heard any noise. Is this quite normal? I want to monitor, but I also don't want to disturb in case she might be doing okay. I wouldn't be able to get a clear view without making such noise and mess of the area. I'm also not sure if she has had more, there really is no noise to indicate such. How long does it usually take? When should I be worried. Thank you so much!