If the test said you're pregnant you NEED to go to your gynecologist and get a blood test done to confirm it.
If you're cramping really bad, to the point where you cannot do anything , you need to go to the ER and tell them you think you might be pregnant.
That happened to my aunt, and she was beginning to have a miscarriage.
If they're smaller cramps though, it could just be because of the pregnancy.