1st pregnancy! Cramp question?

I am just over 4 wks now. I started feeling the  effects as soon as the next day once i got my BFP. I keep getting on and off dull aches around my lower back and lower abdomen. I am work and no one knows yet so its hard for me to focus. Its dull and seems to radiate. Only lasts for a few min then it relaxes for a while. Not sharp pains by any means but its a bit uncomfortable. Anyone else experiencing this? Almost feels like light period cramps. No bleeding and no need for real concern. But its driving me crazy.