9 days late.... Negative test result

I'm now 9 days late on my period. I did a pregnancy test at 7 days late which was negative. I've been getting stomach cramps the whole time my period has been late as though I'm going to get my period, but nothing yet. I came off the 'mini-pill' around 5 months ago but all my periods were on time and regular since that. It's just this one that's been late. I've lost a tiny bit of weight in the last month, but nothing conciderable, so don't think it would be that. I'm getting married in 2 months and I really need my periods to be regular and then I'll know if I will be bleeding on my wedding day (I really hope I don't). I keep feeling faint & shaky, and constantly need the toilet which I know are symptoms of pregnancy, but the test said negative. also just before my period my boobs go massive & rock hard, but they haven't this time. I've never been pregnant before, I'm 28 years old, and worried...why could I be late like this?