Slight cramps in 1st trimester of pregnancy?

i've had slight cramps and i'm only in the first trimester of my pregnancy. after talking to a few people who have had babies, they told me this is normal in the beginning. then twice i've had the slight feeling of being punched in the stomach. it was nothing that i felt i needed to run to the emergency room about but it startled me a bit. i got my bloodwork back yesterday and all my hcg levels were perfect but just wanted to get some feedback since i don't have a doctors appointment for another couple of weeks!