Does divorce occur in the three aforementioned cases, given that one of them was conditional, and the other two occurred in a state of extreme anger, and in one of those, the wife was pregnant?

One must be careful not to be lenient with divorce pronouncements, as haste leads to the disintegration of families. Problems should be resolved calmly and with composure, seeking the help of family if necessary.

Your statement to your wife, "If dawn breaks and you have not brought the child to me, then you are divorced," is a conditional divorce. The majority of scholars hold that the divorce occurs if the condition is not met (i.e., if dawn breaks without the child being brought), and it is considered a revocable divorce.

The other view, which is the choice of Sheikh Al-Islam Ibn Taymiyyah and preferred by the scholars of the Permanent Committee and Sheikh Ibn Uthaymeen, is that the matter depends on the husband's intention. If his intention behind the statement was to threaten and urge, and not to bring about divorce, then he must pay an expiation for breaking an oath, and no divorce occurs.

If the divorce occurs (according to the majority view), you may take her back during the iddah (waiting period) if it is not the third divorce.

Divorce pronounced in a state of extreme anger does not occur, according to the preponderant opinion of scholars. If you pronounced divorce while in a state of extreme anger, then it does not occur in that instance.

It is preferable to refer to the court in matters of divorce to ascertain the details and hear both parties.