Pregnant....?!?

This scares me because I have been drinking and smoking recently due to work being extremely stressful. I don't usually have regular periods but I've never actually missed one. I took two pregnancy test (one 3 days after i was late and the other on the 7th day) last month in December and they came back negative. Fast forward I was supposed to start this month on the 10th, took a test last night and it came back positive. Took one agin this mornin and it was positive. I am concerned because I am the worst type 1 diabetic ever and I need to know how many weeks along I am so I can figure out how much damage I've done. As long as it was conceived after November 8th then the little thing should be okay since that's when I started taking care of myself more. And I have been having some really bad cramp like symptoms and sharp pains in my hip that started about a few days ago. Anyone know how to tell how far along I am? Or if I was pregnant the last period I missed even though both tests came back negative ? I'm going to call and make an appointment with my doctor but the office doesn't open until 9 am