My pregnancy questionnaire, lol

Lu
Hey ladies! This might be sort of long. I'm a first time mom and I just found out I was expecting about 3 days ago!! The doctor (going by my lmp) said I'm 6 weeks, almost 7. However, my cycles were longer than 28 days. Usually more like 32-36. So I'm thinking I'm more like 5 weeks. Other ladies who had longer cycles, what did you go by? 
Also, I haven't experienced any morning sickness so far (thank goodness, that's normal right?), but I am experiencing cramping almost every day. Pretty light and it only hits every once in awhile, but I just wanted to make sure that sounds normal? And one last question. My boobs feel like Mike Tyson has been using them as punching bags for the last week. How long will this last and is there anything I can do to ease the pain? Thanks in advance!