Hello! I am a 17 year old girl. The past two months that's how far I remember I had a 21 day period cycle. I was supposed to get my period yesterday if counting 21 days from the day I finished my last period but not a single bleed was there on the day my period was supposed to come. I had tender breasts, cramps and bloating, acne as I would get during my period or a few days before and cravings. Symptoms of period. I am also wondering could it be the change in my daily routine as I have changed it so much as I have been working before been very active and now I am always at home chilling on the coach, could it be that that might be not bringing on period and could it be going into the 28 day cycle? Also over a few weeks ago me and my boyfriend had unprotected sex with no condom but he hasn't came in me, he pulled out but there was precum, should I take a pregnancy test and if so when is the best time for me to take it and which pregnancy test would you recommend me? Could I be possibly pregnant? - Alicia.