That is not possible. A human can only get pregnant by another human, not by an animal of any kind.
However, there are ethical and legal issues associated with bestiality. You can actually be arrested for it in many places. Even in the places you cannot be arrested, it is widely considered to be animal abuse.
A heavily pregnant cow, or a long-bred cow. Or, a cow that is expecting soon.
Yes.
Yes.
a man could mate with a cow although it may loose something...
A pregnant cow who gives birth is a mother.
No, a pregnant rabbit will not mate. Once a rabbit is pregnant, it will not engage in mating behavior.
No, the cow will not go into estrus after she becomes pregnant.
Bred cow.
Talk to your cow. If she is pregnant your character will mention how see and her baby is doing. If your character does not mention a baby then your cow is not pregnant.
No. Bull Hippos fight each other to decide who gets to mate with the cow hippos. When the baby is born the mother is careful to keep it away from the bulls, as they will kill it in order to make the cow ready to mate again. The next time the cow may well mate with a different bull.
When females are pregnant they start to Mate
Yes. A bull will mate with a cow more than once during her heat cycle if he is so inclined and if he has few other cows to mate with.