Not to discourage further discussion but I have answered a similar question before:

When the Nazis took over in 1933, the Nazi Party flag did not become the German national flag right away. On March 12, 1933 president Hindenburg decreed that Germany should henceforth have two flags: The Swastika Flag but also the old monarchic Black-White-Red flag used before the Weimar Republic.

This was a popular move especially among the political right who had rejected the Black-Red-Gold flag of the Weimar Republic as a symbol of the »November criminals«, i.e. the Social Democrats founding the Republic in November 1918.

This double-flag business lasted until 1935 when at the Nuremberg Party Rally of that year, also famous for the introduction of the Nuremberg Racial Laws, the Swastika Flag was made the sole flag of Germany.

Two reasons precipitated that move: Earlier in 1935 in the course of an anti-Nazi protest in New York some dock workers had ripped down the Nazi flag from a German ship, the Bremen. When tried they were not sentenced because as the argument went, the Swastika Flag was not the official state flag of Germany.

Additionally, by 1935, the Nazis had managed to get rid of the internal conservative opposition. With Hindenburg dead and most of the initial conservative ministers out of the government and some of them even jailed, they felt it was time to complete their grip on power also symbolically by declaring their flag the sole flag of Germany.