movement in my tummy

I can feel movement in my tummy now and it's only 4th month. Is it real that you can feel your baby moving in your tummy at 15weeks onwards? Does it feel like stomach cramp? I dunno how to explain the pain but the pain is there, on and off. My fren told me it's normal cos you really can feel the movement when you're into 2nd trisemester. Strange huh?