I'm 4 weeks pregnant with light cramps but no bleeding is that normal?

Probably. At 4 weeks the uterus is just starting to expand, which may cause some light cramps. Don't worry, but watch for any sign of bleeding or bad pains. For concerns, see your doctor. Otherwise, drink plenty of water, get plenty of rest, and relax.
Braxton Hicks. Braxton hicks contractions are sporadic, irregular, infrequent, painless uterine contractions that usually start about 6 weeks into your pregnancy, and increase in frequency as your pregnancy progresses. It's a bit early but it may be braxton hicks. If it's happening frequently or painful, please go see your OB doctor.