Chest Pain During Pregnancy

Hello I am 5 weeks pregnant and I feel pain in the chest on the left side of my chest. pain comes and goes and last about 2-4 hours. It feels like someone pinching me inside my chest to the right side below my left breast. He did not want to not burn so I doubt it is heartburn. The pain, however, sever or barely noticeable and annoying. What could it be that you've never expereinced this during pregnancy? If so did he go and how long did it last?

I've known that for months now ... lol it hurts. My doctor says that her weight and bad posture ... Try sitting up straight and see if that helps.