late period

so my last period was 2/2-2/8. me and my boyfriend had sex on 2/13. he did not cum and we stopped because we got nervous. we checked every minute or two for pre cum and there wasn’t any. i haven’t really had pregnancy symptoms, just pms. my breasts became sore on monday or tuesday, a little acne, mood swings, etc. my period was expected to start yesterday but it didn’t. my period is irregular sometimes so it doesn’t surprise me but i’m still nervous. i took an early detection pregnancy test twice and they both came back negative. what are the chances of me being pregnant???