I m on doxycycline hyclate for acne , I started on January 23, 3 days before my period and then on February 11 I had unprotected sex and took a day after pill 2 days later and I m scared because its march already, I didn t have my February period and I m always on time that is what is scaring me the fact that im never late i took an early response pregnancy test this morning and it was negative, I talked to my cousin about it and she says it might be the acne medicine, should I wait longer before taking another test or what should I do?