I have a question.
I was civilly married, and now I want to do a kosher Chuppa.
However, my rabbi said that the chuppa cannot be a chuppas niddah? Why not? It's not a second wedding or anything?
Please help me understand this issue.
The issue is since she is not a Besulah (virgin) Chuppah does not acquire the woman, it is the actual living together (ביאה) or being secluded together in a way that they could've been together (יחוד הראוי לביאה). Now, it is permissible to get married in such a manner but they are not allowed to be secluded without witnesses. See Shulchan Aruch Horav Siman 339:8 and Mishna Berurah #32. My assumption is that the Rabbi doesn't want to startup with your feelings of being married yet you can't sleep in the same room (and/or house), he preferred to keep you 'unmarried' until you can 'benefit' from being married. In any case, Mazal Tov!