I'm a week late with my period yet for the past couple of weeks have been getting the signs of the period just not the period itself.

I feel a little bloated in the abdominal area and a queasy feeling that lasted a couple of mornings which are new symptoms,  as well as the usual tender breasts, wind and cramps.

I have taken about four pregnancy tests since feeling the strange symptoms and they have all come back negative.

I'm a bigger woman yet I have always had regular periods. 

Any suggestions on what it could be and what I should do next?