i saw my menses on the 2nd of j7une, i had sex on the 8th took postino2 24 hours later, had sex again few days later and took postinor2 24hours later, and on the 24th of june i had sex and 15thy i noticed some droppings not normal heavy bleeding but droppings and it ran for 7days and stopped, now this months menses hasnt come ,have gone for an ultra sound, ran two pregnancy home urine test and it all says negetifve, can i still be pregnant ?