as long as there is no spotting or bleeding its OK. but if you don't feel good about it, do seek a doctors opinion. they are best at what they do and know better. I experience cramps too and pain. my gynae gave me something to relax the tummy. and I realized that the cramping also came from bloating and wind. passing wind for me has been difficult so I ensure to drink something with ginger to ease with flatulence
I've had it for the past weeks. My gynae said it's normal to experience mild cramps ad hoc as our body is preparing for the baby :) if it worsens, see your gynae