I'm 19 years old,had unprotected sex 2.8 months back, and I've always had delayed period because of hormonal imbalances(pco's) so eversince I has sex haven't had periods, took an hcg urine test four times and had negavtive results all the times, recently my lower back started paining, and tummy is a little bloated could be the delayed periods could I be pregnant?