Shoulder tip pain is an unusual pain felt where your shoulder ends and your arm begins. It's not known exactly why it occurs, but it can be a sign of an ectopic pregnancy causing some internal bleeding, so you should get medical advice right away if you experience it. Shoulder pain during pregnancy can happen at any time, and for many reasons. Most of the time, it's normal. It happens due to changes to your muscles and joints. Causes can include straining your back, sleeping in a funny position, not having good posture, and standing for too long..