You could have taken the test too soon, or you could be getting ready to start your period. Tender breasts and weight gain are symptoms of both. If you're last period was 6/18, don't worry too much, you aren't even really late yet. You may not have a 27 day cycle. If you're TTC, then wait another few days and if you still have symptoms but no period, take another test then call your doctor to have them do a beta.
u should probly wait a week or so.. when is ur period due again?? u can test as early as the very next day of ur missed period.. are u usually regular?? i would wait and see if af shows up and if it doesnt then test... good luck!