This is a common problem for women, and a missed period certainly needs pregnancy to be tested for in the first instance. Presuming that the tests have been done in a technically correct manner, pregnancy is unlikely to be the cause as of now. In absence of the very early symptoms of pregnancy most women are familiar with, the reason for the delay is that ovulation has not taken place timely or maybe not as yet. One generally menstruates about 14 days after the ovulation. The mild cramps may suggest a period in the offing, maybe in next 48 hours. The pain will be in the midline lower down in the abdomen, just above the pubic bone. The stronger it gets the more the chance of the period comming to relieve it. There are many things which I havent said as yet, since you must meet your gynaecologist who will check to ensure that nothing more ominous is on.

you need a check up,delay in periods happens due to other reasons also like some pills taken,emotional upsets etc,urine pregnancy is usually very sensitive and in case of pregnancy if done properly should come positive.If in past you had regular periods then this unusual.if they are in past wait for 2-3 more days.