I am one day late on my period, i had sex but no ejaculation inside. is that a sign of pregnancy?

Probably not, ...: Your described scenario may be just the commonly expected minor variation of period regularity, which has never be perfectly regular all the time among all women. However, as a general rule nowadays, do HPT soon after missing the regularly expected period and repeat it in 1-2 wks if (-) or still in doubt. Also, note: Ovulation usually occurs 2 weeks before the period.