PLEASE HELP.

Sierra

Me and my boyfriend had unprotected sex on feb 3 , last period Jan 19 we never use condoms anytime we have sex and he always cums in me for the most part , my period always comes i never get pregnant. MY PERIOD IS 10 DAYS LATE I HAVE SYMPTONS SUCH AS INCREASE IN APPETITE , FATIGUE , AND NAUSEAOUS . I TOOK TWO TEST BOTH NEGATIVE WHATS WRONG WITH ME