The pregnancy in your dream can be understood as that you are doing something that can carry your hopes for you, or something or work that you have always wanted to do.
If you have a second dream in a row on the same night, or if it is completely integrated with the first dream,
Pants: There are two main functions since ancient times. First, they keep warm. Second, cover up shame and beautify the body;
For modern people, the second function occupies a large proportion. If it is a dream to make trousers for dad and dream that you are pregnant, then your dream can be explained as follows:
You have done or are doing something in reality recently, which is very important to you or you like it very much, and you really want to do it, but after doing it, it may have an impact on your late father's reputation. In reality, you may not realize it obviously, or you may just feel it vaguely.
This reasoning is based on the fact that you are a girl, and your actual data is blank, so I can only give you a rough inference. Please forgive me if the above is wrong.