My Boyfriend And I Have Unprotected Sex Basically Because We

My boyfriend and I have unprotected sex basically because we aren't trying to not get pregnant. If it happens it happens. I am currently 10 days late with mild cramping and some breast tenderness. I have taken 2 pregnancy tests and both showed up as negative. I have never been late before and am just wondering if maybe it's too early to tell. I've heard it takes longer sometimes with some women.