I need advise on traveling by plane during pregnancy.

Scarlett • Hello there. My name is Scarlett. I'm 24 years old, married, and expecting my first in March.
Near the end of my second trimester, I am reuniting with my husband in Germany to live permanently. 
I'm high-risk due to diabetes. 
My aunt thinks I'll die of a blood clot on a such a long flight. 
Any advice, suggestions, or stories they care to share about the best way to travel pregnant? I've traveled a lot in my life, including internationally, but never during pregnancy. I think I'll be exhausted with the layovers, etc. 
Thanks!