Yes, they can be bred and still have appear to be cycling...but your cow made not have taken to her breeding either....are you certain she is bred? A bull doesn't always get the job done in one jump. She may still be open!
I have been told that 10%of cattle have false heats. I went through a period where I think I had a much higher percentage than that. It usually happens in late preg. I had one heifer a few years ago that I bred A.I. twice,then Had a freind breed her for me.She calved to my first service=don't know why we couldn't tell the second and third service,she felt normal. I noticed that the bull I had out with the cows didn't pay them much attention,but the cows were riding like something was going on. Had one cow slip a calf,about 7-8 months along,while she was having a false heat.Think another cow knocked it out of her,not sure.Fetus looked normal,just too early.