Cramps

6 weeks pregnant and the cramps are so bad. Last week I got cramp every now and again and the pain was bearable. For the past 3 days I am getting cramps about 4 times a day and the pain is so bad but they only last 5-10 mins then go away. I haven't had period cramps for about 7 years so not sure if this pain is normal or severe. Think I'm slightly constipated as well so maybe that is causing the cramps?