Any advice for the newly pregnant?

Hi ladies! I'm almost 4 weeks pregnant and I'm experiencing heavy cramping with no bleeding. I'm just having lots of lower abdominal and back pressure and sometimes a sharp or shooting pain. Most of the time the cramps feel like impending period cramps but I have been getting ever-darkening pregnancy tests over the last few days. If anyone could offer any insight or success stories, it'd so put my mind at ease. Thanks so much!