light bleeding 1 week before period

my boyfriend had masturbated and wiped his hands wit tissue and then few minutes later had fingured me. this happened on the 14th of february. i got my period on the 3rd of march and my next one is supposed to be on the 3rd of april. on the 26th of march i noticed some extremely light blood after wiping after going to the bathroom and today on the 27th of march i started bleeding but it is very light and unusual because i never got it like that. i took a home pregnancy test before the light bleeding started and it showed negative. is this bleeding a sign of pregnancy or implantation bleeding?