I'm 29 Weeks Pregnant And Have Noticed That When I

I'm 29 weeks pregnant and have noticed that when I strain to use the bathroom the my jugular or the big vein in my neck swells. I can feel it when it is happening. It also pulsates when I have an orgasm? I have also noticed that it appears larger or more swollen in one part rather than the same size.
Is this anything to be concerned about? Or is it normal due to the increase of blood flow I'm having being pregnant.