Pulled muscle on right side

Melissa
I'm almost 37 weeks and I have had a sinus infection with a cough for two weeks. My dr put me on an antibiotic but I have now developed a terrible pulled muscle on my right side from the cough. It's so bad that I've been in bed all day and can barely move. I'm nervous if I go into labor soon, I won't be able to push because of the pain. Has anyone else had this during pregnancy, and if so, what can you do?