After a couple of months of trying I started getting period pain a few days before my period was due. It was bad enough that I put a pad on before I went to bed because I was sure AF was coming that night but nothing. My boobs also were tender and bigger even at that stage. When I finally did a test on day 28 it was positive! The cramps lasted for another week or so and at one stage got so bad I decided to go the early pregnancy assessment unit at the local hospital to check everything was OK. It was and now I have a beautiful 20 month old boy.
Long story short, cramps a few days before AF is due is a good sign!