Hi!, I Supposed To Have A Period Last Feb 14

Hi!, I supposed to have a period last Feb 14 so I had sex with my boyfriend a day after. I have lower abdominal pain and tender breast since that day and until now I don't have any period yet. It's almost 17days delay. I didn't use any pregnancy test yet bcoz they say that it's really not that accurate. I'm not sure if I'm pregnant or my period is just delay. Pls help. Thanks!