Cramping on its own is perfectly normal! I was 6 weeks pregnant when i found out, and i had had cramping for a couple of weeks which i thought was my AF. Your uterus has to do lots of stretching to accommodate your growing baby, and that can be painful! I had to see an out of hours GP because i suddenly developed a sharp pain in my right hand side, which turned out to be nothing sinister and again normal, and he said that sharp pain aside, cramping is normal and really you only need to worry when its accompanied by bleeding. I have a rubbish body, so i've had cramping throughout my entire pregnancy. True not to worry though, it just makes it tougher until you get your scan