If your husband went to the court or consulted a scholar whom he trusts, and that scholar ruled that the threefold divorce counts as such, then the matter is as he ruled, and you are not permissible for your (ex-)husband.
But if he did not consult anyone or go to the court, then the reliable ruling in our opinion is that divorce issued at the time of menses does not count as such, either as one (talaaq) or more, and that the threefold divorce -- if it is issued during the time of purity (i.e., when the woman is not menstruating) is counted as one divorce. If you husband follows this fatwa, or he himself consulted a scholar who says that it does not count as a divorce, you are still married and no divorce has taken place.
If he consulted a scholar who says that divorce issued at the time of menses counts as such, but he regards the threefold divorce as one, then you have been divorced once (one talaaq) and he may take you back so long as the iddah has not ended.
And Allah knows best.
Reproduced from Islam QA