severe stomach pain one week before the due date

Hi ladies,
Hope someone's still awake... I just got off work (reception, hotel) and I've had stomach ache all day. It's been going on for a few days but I don't mind because it felt like a sign of pregnancy to me. Also very sensitive breasts and nipples and just a feeling that it's a hit. We're going for the third so I know how it feels. But today the pain got so bad that I thought, once I'm done with work I'll race to the urgent care center. And I don't do that lightly. I do notice, now that I've taken off my tight skirt and tights, and with a paracetamol that the pain is decreasing. Doesn't change the fact that how I felt at work today, pregnant or not, it really wasn't normal... what could this be? I came across an ectopic pregnancy on the internet. A miscarriage can't be that early. Does anyone recognize this??? Oh, ps, Monday is my due date