I should be excited, but I'm just worried.

So, after a year of ttc, my husband and I got out bfp on May 2nd. If my numbers are right, we should be about 5 weeks. I have an appointment with my OBGYN tomorrow but I'm just worried shes going to give me bad news... I have one fallopian tube, and its stretched a bit. At least it was in 2012. I'm just worried I'm going to have a miscarriage or be told it's an ectopic pregnancy. I have had very light, and I mean light, cramping but no bleeding whatsoever. Everyone says the cramping is normal. What should I do? I am so happy but all I can think is that this is going to be taken away from us.