All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
If your husband did not determine a dowry for you, then you deserve the same dowry as the women of the same social status like you. For more benefit, please refer to Fatwa 90160.
In case he determined a dowry for you, then you are entitled to it. If this dowry had a known appointed time, then you deserve it when that appointed time comes, and if there was no known appointed time for it, then you deserve it when your husband divorces you or dies. However, some scholars said that it should be paid immediately (i.e. it is due once the marriage is consummated).
Therefore, if your husband divorced you, he is obligated to pay your dowry if he is able to pay it. Even if he does not divorce you, it is permissible for you to ask him to pay it to you.
It should be noted that a husband should not divorce his wife just because she is sick or because he wants to marry another wife. Rather, he should keep her if possible and have good marital relationship with her especially if he had children from her and they have been married for a long time. Allaah Says (what means): {And do not forget graciousness between you. Indeed Allaah, of whatever you do, is Seeing.}[Quran 2:237]
Allaah Knows best.