With most tests you can get an accurate result up to 5 days before your missed period. Go to the drugstore and buy a multipack of home tests. Take one 5 days before you expect your period. If it is negative wait and take another on the day you expect your period. If it is still negative and you haven't gotten your period yet take one 5 days after your expected period. By then, if you have had fairly regular periods in the past, you should be getting an accurate result. So the only thing you can do is relax as best as possible and wait to take the tests.