I am a 23 year old married woman, and until very recently I've had a fairly regular 33-34 day cycle. I am not on the birth control pill, nor am I taking any medications that would effect my hormone balance. Two months ago, I was a few days late (approx. 37 day cycle), but didn't think much of it. The date of my last menstrual period was 7/27, and I expected my period to come last Wednesday, 8/31. I am now nine days late -- on day 43 of this cycle. For the past week or so I have gotten very light cramps off-and-on and have had sore breasts similar to what I typically experience before I'm about to start my period. I've taken 3 pregnancy tests in the last week since missing my period and all have yielded negative results (I'm assuming I'm not pregnant as the home pregnancy tests claim to be sensitive enough to detect pregnancy even before a missed period).

My question for you is this... Is it common for a woman to miss a period after being regular for so many years? Is there still a chance I could be pregnant? Should the cramps and sore breasts be a cause for concern?

Any advice that you can give would be greatly appreciated! Thanks so much!