Pulling feeling on right side....

Morning ladies. So af is due today (boo). I've done a few ic tests this week and an Asda cheapie this morning, all bfn so fully expect her to arrive at some point, but for about a week now I've had a strange pulling feeling on my right side (pelvic area). It's like a tugging sensation. I've never felt anything like this. Has anybody felt anything like this before? It's not like af cramps atall. It's still there now. It's been pretty much constant for a week.