What Causes An Abdominal And Back "pulling Sensation"?

Hello. Its late so I wanted to see if I could get a quick opinion until I can make an appointment to see a doctor. While exercising today, i noticed I started to feel a pulling sensation in my lower abdomen on the right side. I also felt it in my back. There was no pain, but it felt like something was going to fall out of me. Any ideas as to what could be going on?