change of tax class after marriage (Munich)

Dear Expats,

I am writing you in order to get some more information about the above topic.
I got married last week in Bosnia, where my husband still lives ( he will be able to move to Germany only in July, due to his job and commitments).
I went yesterday to Finanzamt and they gave me the application form to change my tax class from 1 to 3, but said as well that this will be possible only when my husband will come to Germany.
Does it mean that i have to wait till July to apply for a tax class change? Will they calculate my new salary and tax deduction based on the date of my marriage, or of the residence registration of my husband in DE?

If you had any similar experience or can give any advice, it is much appreciated :)

regards
Samra