Lower back pain

Maddie • 20 years old 2 -angel babies

Hello! I’m 3 weeks 6 days pregnant! Tomorrow would have been the day my period was due. When I get my period I have severe cramping and dull lower back pain. I just noticed my lower back is full hurting and I have very dull cramping, not constant just every once in awhile, should I be worried or is this normal?