Tdap (Whooping Cough) Vaccine during Pregnancy?

Yasemin
Hey ladies! My Ogbyn recommended me to do flue vaccine and whooping cough vaccine at 26weeks. I'm currently 24weeks and have two weeks to decide if I wanna get the vaccines or not. 
I read that Tdap is class C and not proved to be 100% safe during pregnancy. Also many ppl say that it causes stillbirth. It's not directly linked and there is no scientific articles about it; however, it's mostly mothers on forums that are talking about how their baby stopped growing at certain time and it all dated back to when they got the vaccine. 
Flu Shot, I will be declining but not sure about whooping cough. Let me know what you think!