hello, i'm 17 years old, and yes, sexually active, i have only had two guys all my life sexually. my boyfriend and i have had sex quite a bit, but the last time we had sex, he noticed there was blood, so at first i felt embarrassed because it could have been my period, and he was fine, and thought the same thing, but the thing is, after he left and i double checked, there was no blood, no signs of my period. what can this be? i'm scared and i also have been getting paranoid over pregnancy, because my period has skipped a month now which is weird, can someone please help me, thank you so much!