Ruling on Divorce during Pregnancy in Islam
Question

My husband divorced me while I was pregnant, then before I gave birth to my child, he came back and said that we are not divorced since pregnant women can’t be divorced.  So I would like to know am I really divorced or not.  My husband and I love each other very much and now we have a baby son.  Please do reply to me as soon as possible.
Praise be to Allah.Shaykh Ibn Baz (may Allah have mercy on him) was asked whether a woman may be divorced by Talaq when she is pregnant . He said: 
“This is an idea which is common among some people. Some of the people think that a pregnant woman cannot be divorced by Talaq. I do not know where they get this idea from, for it has no basis in the words of the scholars. Rather the view of all the scholars is that a pregnant woman can be divorced by talaq . There is consensus on this point among the scholars, and there is no dispute. 
Talaq according to the Sunnah means that a woman may be divorced in two cases: 

She may be divorced when she is pregnant ; this is a Sunnah divorce and is not Bid`ah.
She should be Tahir (pure, i.e., not menstruating) and her husband should not have touched her (i.e., had intercourse with her), i.e., she should have become Tahir following menstruation or postpartum bleeding and before he has intercourse with her. Divorce in this case is in accordance with the Sunnah.” (Fatawa At-Talaq by Shaykh Ibn Baz, 1/45-46) 

So long as he took her back during the `iddah, then she is still his wife, because the `iddah of a woman who is pregnant ends when she gives birth, and her husband took her back before she gave birth. Allah says (interpretation of the meaning): 
“And for those who are pregnant (whether they are divorced or their husbands are dead), their `iddah (prescribed period) is until they lay down their burden.” [At-Talaq 65:4]
This is the `iddah of the pregnant woman whether she is divorced or widowed. The husband should count this as one talaq.
And Allah knows best.