Vanaithi - I still have my fingers crossed for you. I didn't notice any change in my sleep until I got to about 5 weeks pregnant, and then I got insomnia. I would have trouble falling alseep, then wake up through the night and have trouble falling asleep again. Oh, and I keep waking earlier in the morning than usual (which is odd for me because I love my morning sleep time).
Don't lose to much hope because of the cramps. When I was pregnant I had a sensation down in my uterus similar to what I feel when I am about to get AF, except I felt it the entire time I was pregnant. Apparently that's pretty normal (uterus expanding and all that...).
Fingers crossed your temp dip was implantation!